The thief's blackbird quest in the QfG series:
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There's one real blackbird and four fakes. You get to see the real one in the first game (remake), but because you have no idea what it is or its value, you can't take it. Then you finally learn about it in the second game and get a chance to steal it for Ferrari, except it's a fake. You see another one in the third game in a thrift shop, it's a fake. You find a fourth one in the monastery in town, another fake. Finally, at last in the fifth game, Elsa clues you in about the location of the real blackbird. A fitting end after all the trouble.
It's not like it's an all-consuming quest, but once you know about it, you try to keep an eye out for it.
Lee's revenge in Gothic 3: It isn't much, but I always make sure my bro Lee gets his stone after all we've been through together.
Does the guy trying to get his item returned in all three Mass Effects count as a quest chain?
Ultima VII: Fellowship member has glaring moral fault, gets caught and either has to make amends or dies karmic death. Oh, was that a spoiler?
