Angel and Groo hurry through the sewer tunnels. Angel suddenly stops because he can sense evil. So can Groo, so he wants to rush forward, but Angel urges caution. He also calls Groo "Champ," which makes me twitch. Groo hands Angel the prophylactic potion and asks him to keep it safe, then charges forward. Angel sighs and follows.
In the treehouse, Groo is hacking away at roots while Gunn and Fred urge him on. We see a one-eyed face in the tree's trunk, which growls at Groo. ["Oh. Well, then, I have no objection to the idea that a demon tree would have a DSL connection and use it to lure lonelyhearts to their deaths. Cheers!" -- Wing Chun] A root lunges out and plunges into Groo's chest, yanking him forward. Angel enters with a dramatic flourish, takes in the situation, and whines, "That's my shirt!"
Angel picks up Groo's dropped sword and asks if the tree is made of wood. Fred says, "No, it's flesh," and Angel says that's good. Fred expositions that the tree "uses people as batteries." Gunn adds that it's gotten stronger since it captured Groo. Which was thirty seconds ago. Gunn's got some keen senses there. Angel snaps, "C'mon, [Groo] can't be that great!" He drops the sword, wanders over to the tree's "face," and asks if Groo is really all that. The tree slurs, "Hesh magnifishent." Angel isn't convinced. He wanders over to Groo and says, "I'm really getting tired of the Groosa-worship thing!" Then he punches Groo, causing the tree to scream. Angel goes on complaining that "he's such a champion. He's so rugged! He's so emotionally available!" punctuating each gripe with a punch. The tree keeps roaring but does nothing to shove Angel away. Stupid tree. Angel finishes, "I'm smarter, and I'm stronger, and I pick out my own clothes!" With a final two-handed club to Groo's neck, he finishes venting. The tree pulls its root out of Groo and drives it into Angel instead. Angel makes some lame quips, and the tree realizes that he's a vampire because no mere human could quip like that. It moans, "Cold, cold." I don't know why attacking a vampire makes the tree lose power, but it does, and there are so many other things I don't understand here that I see no reason to pick on that one in particular. ["Really, once you're confronted by a demon tree, you just have to realize you're overmatched, and give up." -- Wing Chun] The roots holding Gunn and Fred wither, and Fred and Gunn start working to free themselves. Gunn picks up the sword while the tree keeps on whining that it's "so cold." Gunn plunges the sword into the tree's eye and snaps, "So dead!" So dumb. Sure enough, that happens to kill it. The tree dies, Angel stands up, and Fred checks on Groo. She says "he's still alive, thanks to [Angel]."