Tatsuo is more or less following what Togusa is talking about. There was the place the subway went to a few months back that people were building things in. Though... he hadn't tried it himself.

"What do we have to build with though?"

He starts patting down his pockets, thinking about what he has on hand. Pocket knife, wallet with cash and cards, pistol, two cellphones, keys, pen... not much.

"Or is this like one of those locked room riddles? A guy is in an doorless windowless room with a table and mirror, how does he gets out?"

Because he can never remember the proper answer to that riddle.