Hopping in to say that Thancred will be using the lockpick he found from this investigation, which he is fairly certain must be Babis', in order to try and open the lockbox. This will be a way of flexing on him to show that it seems he apparently already thieved something of his. Time to see how that goes!

Geralt will hang back and supervise this, but he's going to be keeping a close eye on Babis in particular, observing his reaction.