It is night in a desert ruin. Archaeologist Samuel Kellig is calling for someone named Hassan. He gives the young man a box and tells him to run to the village and send it right away. After Hassan has gone a beautiful woman, Jessica Lancy, comes out of the ruins, and demands to know if Samuel is leaving her. "I have to," he tells her, very agitated. "You can't," she says, and compels him by some strange force to come to her. "No," he denies, "you're not Jessica, you're something else. I know what you're doing to me now, I know where you came from." He says he'll stop her. When she insists he tell her where "it" is, he resists, but she backs him into the tent, saying with complete certainty that he will tell her everything. She rips open his shirt and caresses him, and we hear the sounds of an animal growling. He knows she's feeding off of him, he says; yet he still wants it, she purrs, no matter what happens to him. Frightened, he protests that she needs him to live. "Not any longer," she tells him, and demands to know where the urn is, her eyes turning yellow and slitted. Samuel resists, begging for his life.
Outside, Hassan has delayed leaving to see what is happening. The box he carries is addressed to Derek Rayne on Angel Island. He witnesses, as shadows on the tent wall, the woman become a giant snake and devouring Samuel.
At a park overlooking the ocean, Derek is reading Samuel's last letter to him, telling him about falling in love with his assistant Jessica Lancy. He looks forward to bringing her to meet Derek, when he will see why she reminds him of Byron's poem, which Derek recites: "She walks in beauty, like the night of cloudless climes..." Unexpectedly, a woman finishes reciting the poem, then introduces herself as Jessica, Samuel's fiancee. She had come looking for him, knowing how both he and Samuel loved this park. His death was such a shock, she says, and she reassures him that there was absolutely nothing he or anyone could have done. The propane tanks had exploded, and animals must have gotten to his body. Derek offers comfort, giving her Samuel's letter, and she tells him how kind he is, "so much like Samuel," and kisses his cheek. Derek seems a bit uncomfortable and changes the subject. He finds that Jessica is staying at Samuel's loft to take care of his things. After she refuses his offered lift, he makes certain she has his number. If there's anything she needs, he says, call him. After he leaves, she crumples up the letter. "I will," she says, and there is subtle menace in her voice.
Over coffee at home, Derek tells Alex and Kristin about his friendship with Samuel, of nearly 20 years. They're looking at a picture of the two men, taken in Tibet. They're in the mountains, unshaven, arms around each other's shoulders grinning at the camera. "Looks like Day 9 of the Hostage Crisis," Kristin remarks with a smile. "Close," Derek admits; they'd just escaped from a Chinese cell where they'd been held for over a week. By hang glider, as Alex recalls the rumor. Derek smiles, saying Samuel must have put that out about. The truth was that their guards got drunk and forgot to lock the cell door. Alex asks how Samuel's fiancee is managing, and Derek says as well as she can under the circumstances. "Jessica Lancy is a very unusual woman...Quite different than I imagined." "Not the usual ‘dusty and boring' archaeologist?" Kristin queries. Derek says that isn't quite what he meant; for the 3 years she'd been Samuel's assistant he had barely ever mentioned her, and then he suddenly woke up two months before and realized he loved her, proposing on the spot. Derek is very puzzled.
Samuel's package has been delivered, and the three discover it contains a shattered Minoan artifact. There is no note, but the address was definitely in Samuel's writing, and it came from a village in Turkey. Kristin wonders what a Minoan artifact was doing in Turkey. The writing on the pottery is cuneiform; Derek says Samuel understood the language as well as he, so why send it to him? It must be important, and he tells Kristin and Alex he must know what it says.
Rachel arrives back from a conference, to discover books and papers spread all over the library. She's perturbed, since she'd had an important project on the table and it's been moved. Kristin introduces herself, apologizes for having to move Rachel's papers (she needed the space and didn't know when Rachel would be back). Rachel is angered to realize Kristin has read her papers, and obviously believes her responsible for losing an envelope containing her report to Derek, even though Kristin denies having seen it.
In the Control Room, Alex and Derek are having difficulty determining the purpose of the broken pottery. They'll need to reconstruct it before they can read the cuneiform inscription; Alex draws this task. Derek has a sudden flash of a vision of a naked woman in bed, hears the animal-like growling, and is quite disturbed. He suggests the vessel may have been used in some fertility rite and turns abruptly to leave. When Alex asks where he is going, he counters with, "I wasn't aware I had to account for my whereabouts." Kristin passes him coming in and wonders to Alex if he's all right. Alex thinks Samuel's death is affecting him more than he's letting on. Kristin tells Alex about her meeting with Rachel, and describes it as "a little bit like docking the Hindenburg." A woman of unshakable convictions, she observes; Alex says that when Rachel believes something she doesn't hold back and Kristin will get used to it. Kristin says has the distinct feeling than Rachel doesn't like her, and when Alex suggests they need to find something in common remarks, "Well, we are both mammals..."
At Samuel's loft, Derek asks Jessica if she knows anything about the shattered Minoan artifact, and she claims she doesn't. Maybe if she sees it... Derek says there's not much to see, tells her it will be difficult to reconstruct but if Samuel felt it important enough to send it to him he thought she might have known why. She admits she had trouble thinking about those last few days. Derek embraces her to comfort her and gets flashes of the two of them entangled together in bed. He's profoundly disturbed and tries to leave. She seeks to delay him but he insists. She then gives him Samuel's field box, a small wooden inlay box he always took with him. Derek says he claimed it had magical powers. She tells him she couldn't bring herself to open it and asks if he'll go through and catalog the contents for her "and Samuel." He agrees. When she presses him with "...and you will come back?" he, obviously reluctant but almost compelled, answers simply, "Yes."
In bed that night Derek's sleep is disturbed by the sound of Jessica calling his name. We see her in bed at Samuel's loft, as she whispers Derek's name, running her hand sensuously along her naked thigh which shimmers like snake skin. In Derek's room, Samuel's field box is open on the nightstand, and from the piece of pottery shaped like a serpent's eye a light blazes forth. Derek is writhing in a bed with Jessica, protesting that this is wrong, but she denies that and insists he kiss her. He repeats "No...no..." over and over, his face showing his torment and compulsion as he makes love to her. Finally he is flung out of the "dream" with a loud cry of "NO!" and sits up in his own bed. Leaning across to get a drink of water from the cup on his nightstand, we see red scratches from a woman's fingernails down his back.
The next morning Rachel is telling Derek about the conference, and admits to a setback as she can't find the report she needs him to read. "In the envelope?" he asks. "I've already read it while you were at the conference." He apologizes for having caused her any problems, but he confesses to having a lot on his mind and tells her about Samuel's death. She is sympathetic, offering to help. He asks why someone would dream about a situation they believed was wrong, and she suggests that sometimes people can work things out in dreams they can't in waking life. "Like a taboo," he says, and she agrees. When she asks him to go on, he tells her he has to work it out himself.
Alex and Kristin are working on the urn, Alex putting it back together and Kristin working on the translation. The language is all very confusing but seems to indicate something about feeding in–or on–dreams, and of fertility or procreation, unusually direct for this culture. There is a strange scale pattern on the inside of the urn that they cannot figure out.
When Rachel and Kristin "encounter" each other in the library, Rachel attempts to apologize for her actions earlier, but drops some books before she can get started. When Kristin tries to help she insists on getting them herself, and Kristin remarks that Nick said she was independent. When asked what else Nick had said, she hears that Nick considers her a good ally to have in a fight and she always acts with the best intentions. When Rachel skeptically warns Kristin not to believe everything Nick says since he tends to over-exaggerate, Kristin agrees. "He called me impulsive," she says, to which Rachel replies that that's like the pot calling the kettle black. "I bet he said I overreact," which, she admits, is not always wrong, and she explains about the missing envelope and apologizes for jumping to conclusions. "No harm done," Kristin assures her.
In his office, Derek is examining the contents of Samuel's field box. When he picks up the pottery snake eye he hears rattling and has a vision of Jessica in a negligee, looking up at him with yellow snake eyes. He hears someone playing the Moonlight Sonata and goes downstairs to investigate. He finds Rachel at the piano, wearing a low-cut red velvet gown, looking sexy and dreamy. "Rachel? What are you doing?" he asks. She reaches out, caresses his cheek and leans close as if to kiss him. "You know," she whispers. "No–I don't know. I don't understand." She pulls away, and when he puts his hand over hers on the keys she turns into Jessica. "Don't you?" she asks. Standing, she cups his face in her hands. "You want me. Submit to me." Just as it seems he shall give in, he grasps her hands and pulls away. Now she's Kristin. "Haven't you always known?" She kisses him, and he again gets a flash of Jessica writhing naked on top of him and pulls back once more to see Jessica before him. "Give yourself to me," she says. "You brought me by wanting me the same way that I want you." It's wrong, he protests, tormented. Samuel's gone, she argues. All Derek has to do is destroy something for her. Unwilling yet unable to stop himself, he kisses her. He pulls back from her again as she urges him to stay with her. But he hears Rachel shouting his name, and suddenly he finds himself standing in his office, Rachel before him calling him.
Rachel tells him he was shouting Samuel's name over and over, and she couldn't get his attention. His office is in a shambles. "We have to talk," she says, and he tells her not now. "Yes, now," she insists. "I need time," he tells her, then moderating his tone, says "Please?" She agrees, but says he needs help. After she leaves he begins to straighten his office, but when he discovers his notepad with the name Jessica written over and over, he starts hearing the name repeated in his head. In desperation, he throws his monitor across the room.
In the Control Room, Alex has made good progress on reconstructing the urn. When Kristin admires her work and jokes that she missed her calling, Alex offers to trade places. Kristin, amused, refuses. "I'm having way to much fun in my crash course in a dead language," she says. They puzzle over the snake scale patterns on the inside. Perhaps they had put a reptile inside, but there is no organic residue inside. And if it had been just a dead snake, Kristin wonders, why would they write a warning on the outside of the urn?
Derek is finally speaking to Rachel, but it is very difficult for him. She suggests he may feel guilty about Samuel's death, but that isn't what's wrong he says. It is strange dreams he is having about Jessica– "Intense, strange...highly erotic." It isn't just attraction, but some kind of electricity between them. He's never felt this way about anyone, and has no control over it. Rachel suggests that he's always had too much control, and someone has finally gotten past his armor. She assures him he's neither "repressed or obsessed" but tells him his grief can be affecting how he feels.
At Jessica's that afternoon, he tries to tell her how he feels, that from the moment he saw her he began to fall in love with her. He tried to fight it, because he felt it was wrong. She confesses that she felt the same. "I know you loved Samuel," she says. "I loved him too. But he's gone, and we're alive. I'm alive." She asks, "Do you want me?" "Yes," he says, almost despairingly. "Oh, yes." She leads him to her bed, and she takes off her blouse and skirt and moves on top of him...
Kristin has found a scrap of writing on a piece of the paper used as packing material in the crate the urn was shipped in. She and Alex frantically search for the rest of the fragment and find the word "Catticus," a buried city in Turkey, the city of the dead. So Samuel sent a note after all–but what was he trying to tell them?
Derek and Jessica are totally involved in their love making, Jessica still controlling it. As they (how shall I phrase this delicately?) achieve satisfaction, a strange light shimmers over Derek's chest, and the scale pattern appears on Jessica's back.
It is night time, and Jessica and Derek lie together in her bed. She tells him he has an intensity in him "like the coals at the center of a fire." Derek is strangely weak, and concerned over how long he's been there. She wants him to stay with her, but his cell phone rings. It is Alex to tell him they've almost finished the urn, but there's something about the inscription he needs to know and he should come see it. Jessica thinks he'd better go back and find out; she offers to take him because he doesn't look very well...
Kristin believes the inscription is an incantation, protection against whatever was in the urn, feeding on people in their dreams. But they don't have the complete incantation, and they haven't figured out what Samuel meant by "Catticus." A pity Samuel never saw the urn whole, Kristin remarks, which causes Alex to speculate that Samuel himself might have broken it, releasing something terrible on the world, which is why he sent it to Derek.
Jessica brings Derek home, and Alex meets them in the foyer. He looks very ill, and Alex tries to take him upstairs as Jessica leaves, after asking Alex to call her to let her know how Derek is. Alex tells Derek on the stairs about the incantation and thinking that Samuel himself broke the urn and released an evil spirit. Even though Alex urges him to rest Derek demands to see the urn *now*. Alex agrees to bring it to his room.
She was right, he tells her after examining the inscription. Something that feeds on the souls of men was imprisoned there and the only way of catching it again is to read the incantation, calling it by name. But that piece is missing. Alex again tries to get him to rest, but he's insistent about continuing. He's puzzling over the name "Catticus" as a worried Alex leaves him. Suddenly he figures out that it doesn't refer to the city, but the man, as he takes the works of Catticus from his bookshelf.
Jessica, meanwhile, has not left. She's in the house...
Rachel arrives, looking for Derek, and Kristin tells her he's ill and Jessica brought him back home...
Jessica is climbing the stairs...
Rachel is worried about Derek, who hasn't been like himself since Samuel's accident. Kristin tells her it may not have been an accident, and tells her about the urn and inscription. She's also discovered that Samuel, who used to faithfully file weekly Legacy reports for years, suddenly stopped shortly after becoming engaged to Jessica. This causes Rachel to remark in bewilderment that the woman certainly seems to have an unusual effect on men.
Derek discovers in Catticus what the evil force is called–Lamia. Jessica comes into Derek's room and reaches him before he notices she's there. "It certainly took you long enough to invite me into this house," she says. Backhanding Derek across the room, she approaches the urn. Derek cries out as she reaches for it, and tries to lure her to him. "It's me you want. You want my power. Finish what you started." "I will," she vows, and flings the urn against the fireplace where it shatters once again.
Alex tells Rachel that Derek is ill after having apparently spent the evening with Jessica. Rachel marvels, "what is it about this woman?" and the effect she has first on Samuel and then Derek. Kristin has her picture up on the screen, a mousy-looking woman with bad hair and glasses. "That's not Jessica Lancy," Alex declares. "The woman I met was magnetic, sensuous." "Not the usual boring, dusty archaeologist," Kristin remarks. When Rachel says they need to talk to Jessica, Alex says she's left and Rachel must have passed her on the way out. When Rachel declares she didn't pass anyone they all rush out, alarmed.
In his room, the lamia is again seducing Derek. He tries to speak the incantation, "Begone, evil one. Begone from the earth..." but she hushes him and brings him under her spell again. "Do you think you can resist someone as ancient as me? I have been feeding off your kind since time began." Derek tries but is unable to break free of her, as she compels him to kiss her. Just then, Rachel, Kristin and Alex rush in, Kristin crying out to Derek to get away, she killed Samuel. Rachel attempts to strike the lamia as Alex yells to Derek to open the field box. The distractions were enough to allow him to break free and Derek finishes the incantation. The lamia spirit screeches as its snakelike form is compelled from Jessica's body and into the box.
Handing the closed box carefully to Rachel, Derek goes to the sprawled form of Jessica Lancy, once more herself. She is shaken, weak. Looking at him in puzzlement, she quavers, "Do I know you?" "No," he answers gently, "we've never met." Cradling the bewildered woman comfortingly in his arms as Kristin, Alex and Rachel look on in concern, we hear Derek's journal entry:
"Passion...it has the power to elevate us, drive us to our greatest achievements. Yet without love to guide it passion can be the destroyer, consuming everything in its path. We are defined not by the strength of our passions, but the depth of our love."