Rewritable Memory
Recapping previous sessions is more difficult than it should be. Someone should be writing this stuff down. But anyway, our Deathwatch marines got in to some bother on the space hulk, and it was down to one of the characters to work out what was going on to save the others. It's somewhat ironic, because the player of that character doesn't remember a whit of what happened.
'That may be because we wiped your memory with a pen.'
'Oh, one of those little flashy things?'
'No, an actual pen. We just stabbed through your eyeball until we hit the specific memories of last week. There, uh, may be ancillary damage.'