Turns out that the amulet that Spike used to destroy the first/uber-vamps/himself was "donated" by Wolfram and Hart and that it is mystically linked to them (for some reason specifically the LA branch). This somehow means that the spirit of Spike is also tied to them and is also being drawn to hell - kind of like some post-death holding pattern/limbo. They set about finding out how to release Spike from the amulet which may or may not send him to hell/make him "whole" again which takes quite a while. The "find him a body" business comes quite early on into the season when they deal with a human magician/necromancer who specialises in putting demon spirits into human bodies and they dupe him into putting Spike into one so's they can "bust" him,so Spike remains incorpreal for a while longer. He comes back properly eventually though, but I'm not gonna tell you how - you'll just have to watch! Sky1 Tuesday nights, repeated on Sat nights, but I don't if/when C4 or any other terrestrial channel will be picking it up.