Did I miss a promotion ? (COD Black Ops 2 Trade)

Then I would fear it's stolen. Play it as much as you can now lest it get revoked later for a CC chargeback.

Something similar happened to me. Trade stuff, then the thing that I received got revoked by Steam. I then contacted Steam support and explained everything. At the end they return the game. but idk if this applies to everyone.

The game was Torchlight 2 btw.. This happened around last year.. I think..

Yup. Play it now. This reeks of bad juju.

Actually it's more like the guy buying it from some dodgy guy that stole it and the police coming around to reclaim it...

If you buy a stolen car, you don't get to keep it. Doesn't matter how much you paid for it...

If the Black Ops purchase turns out to be fraudulent, it will disappear from your library. Item/gift trades done through the trading system can be reversed, although you may need to contact support and ask for it. But since you gave this person serial numbers, there's no way for Valve to reimburse you. So you'd lose the Black Ops, plus the money you spent on the Sherlock Holmes games, and get nothing back.

p.s. Do you understand why this trade is ridiculous? You paid US$4 for those keys (or possibly zero, if you got them during the glitch) and expected a US$40 game (on sale) in return? Good luck friend, but you might want to stop trading, you're going to be making one of these threads every week... :(