It's not a terrible card; 2 icons and a "return to hand" effect is a nice hedge against failure, but I am not sure how often this will get played, given that 2 XP in will get you a Peter Sylvestre (2), "Look what I found!" (2), .18 Derringer (2), or 2 copies of Brute Force or Sharp Vision. I suppose Silas might like a situation where he contributes this and something else for, say, a +4 to a skill test, draws badly, then pulls the second card back with his Reaction Ability and this back with its own ability. That would feel pretty good.
The reason you take this is a little tricky. But it allows you to fail by two less on test you would never pass, with things like old keyring and look what I found. In a deck that uses covenants and blessed tokens, you can guarantee you get a two on the chaos token, +2 from unexpected courage, then you can drop Oops, Dumb Luck, look what I found or anything else… Then keep unexpected courage. With granny Orne, you can adjust your values even more, if you want to pass by zero or fail by one and keep this card in your hand.
It’s also great to give to allies, if they don’t pass, oh well, next time they might! And you can recur it with True Survivor. Neat how one little sentence can make a card worth two XP.
This card does a couple things that are inobvious.
1: It makes repeat testing to beat a hard challenge more consistent. You know that moment when you've just got to try a test, and your odds are low but plausible? You might commit a card like Overpower or Perception but that'd only get you up to a net +1 over the difficulty. This version of Unexpected Courage can do precisely this, it does'nt guarantee the success on the first action, but it'll come back and give you another go, so that hard you're gunning is'nt "so hard that it's not worth trying", it's "Successful eventually".
To give you a precise case: a Wendy Adams trying to get the last clue from a 4-shroud like the Cellar. Ye's it might fail the first time, but it's certainly worth trying for.
2: Pump numbers for "Fail to succeed" events, the likes of "Look what I found!". Sometimes you'll encounter a hard spot, like Cellar, and a Wendy Adams attempting to pick up clues from there might struggle to even play "Look what I found!", especially on Hard difficulty with very big penalties in the bag. Unexpected Courage pumps the numbers, so you'll either succeed or drastically improve your "Look what I found!" chances. And it'll come back too!