On Halloween night, the Manticore creatures fearlessly prowl the streets; Max must deal with a stubborn nomlie whose head has separated from his body.
Max enters Logan's apartment to find him and Asha working on an investigation. He doesn't need her help on this one, and Max is feeling a little replaced. She invites him to a Halloween party at Crash, but he thinks he'll probably be busy with Asha all night. Max is bummed, but heads for work. Rafer is there, and he mentions that he'll be at Crash for the party. Some little trick-or-treaters come knocking on Joshua's door, and they scream when he opens it. He screams as well, but Max assures the kids that he is only wearing a costume. Joshua asks if he can go out because it's Halloween and no one will notice him, but Max wants him to lay low.
Rafer shows up unexpectedly at Max's pad while she's in the bathtub. He asks to take a detour before the party - to his mom's house. Serena, who has heard all about her son's date, is a psychic, and she reads Max's fortune. Serena sees in her crystal ball that Max's name is only a number. She also predicts danger and death ahead of her. Suddenly, Max sees Joshua outside Serena's window and she goes outside. Joshua has found Sally, a Manticore refugee, on the ground. Sally's body lies face down, but his head is face up. He explains that he was built with no bones and only cartilage, so that he wouldn't fracture on the battlefield. Max tries to wring him around, but Joshua twists Sally's head and it snaps off. Sally's head, however, is still talking, as his body runs off into the night. With starfish in his cocktail, Sally's body parts are self-sustaining and regenerative. He explains that his body has a mind of its own. Rafer appears, and Max throws the head to Joshua. Sally wants to call other transgenics for help, and Rafer drives them in his ambulance to look for "some friends" on a "scavenger hunt." They meet up with Dieter, a reptilian 'nomile wearing a football helmet, and Katarina, a feline-enhanced prototype. Rafer thinks the strange characters are merely normal people wearing costumes. Sally gives up that he was supposed to meet a girl at Crash, so the gang heads there, thinking the body has already gone ahead. When they arrive, Max spies Logan and Asha making out in a booth across the bar. But it's not really them - just two people who look similar. The couple does, however, point her to a back room where the headless body was seen. Sally's body darts out the door, grabbing a high-powered rifle on its way out. Rafer and the transgenic crew pile into the ambulance to chase the body, which flees on a motorcycle. But Rafer's wheels run out of gas, and the body gets away.
Sally fesses up that his body has a rifle because he's on a mission for Manticore and Pierpont Lempkin. Max figures out that Lempkin must have been Logan's button man for Manticore, and Sally is his hitman. Logan gets word that the target may either be one of a priest, a minister or a rabbi who are outspoken leaders in the community. Max gets Sally to admit that it is a Father McAllister, just as Rafer gets a good look at the decapitated head talking. Max coldcocks Rafer to keep him quiet, and she gathers up the mutant gang to search for McAllister at an award dinner run-through. They split up, and Max finds herself face-to-face with the barrel of the body's rifle. It fires at her, but she fights the body off. Sally's head distracts McAllister so that the body can shoot the priest. As it takes aim, Max comes after the body and kicks it in the crotch. The other transgenics take Father McAllister to safety, and Max makes up a story that it was all a Halloween prank. Suddenly, Logan and Asha arrive to take all the credit and ask the priest to marry them. Then Normal, Sketchy and Rafer burst in with a phalanx of riot police. They slap handcuffs on Joshua, Sally, Katrina and Dieter, and ask Max if she's one of the "creatures" too. She sadly says that she is not one of them.
Max sits on the Space Needle, lamenting about only wanting a normal night out, when Original Cindy appears. They both have a quick flashback of Joshua asking to go out, Max telling him no, and O.C. pleading his case. O.C. tells her that the worst part of the horrible evening was that Max denied who she really is. Strangely, Max sees that she is naked atop the Space Needle. Something's not right. She wakes up to find that the whole night was a dream, and she is still in her bathtub as she had been earlier in the day on Halloween. O.C. reminds her to get her costume ready for the party at Crash, but Max says that she isn't going. Instead, she goes to Joshua's to check up on him. He is laying low, like she told him, but Max offers to take him out for the night. On the street, they come across a headless body. Max winces, but realizes it's just a harmless trick-or-treater. She takes Joshua's hand and they head off. It's a good night.
'Boo' was written by Charles Eglee and Moira Kirkland Dekker. Few shows can pull off a quality Halloween episode. BUFFY has done it several times of course, but I can't think of another show that has done it right now. Now DARK ANGEL has joined BUFFY with this episode however. It's definitely a classic. Goes back to the fun of season one. After this episode, I'm starting to miss the fun of season one. Episodes like 'Art Attack'. Okay so that was really the only fun episode I can think of, but...