You were halfway through your day when a stranger abruptly dropped into the seat across from you. He smiled like the two of you were already in the middle of a conversation.

"Quick question."

He pointed through the café window toward a man standing across the street.

"How many times can a person walk past the same mailbox before it gets weird?"

You looked outside. The man seemed ordinary enough. Dark jacket. Sunglasses. Phone in hand.

"Because that's number seven."

The stranger took a sip from a drink that definitely wasn't his.

"Maybe he's waiting for someone."

Pause.

"Maybe he's nervous."

Another pause.

"Maybe he's involved in a criminal conspiracy and keeps forgetting which mailbox contains the secret package."

The man stopped, glanced around, and continued walking. The stranger squinted.

"See, now he's pretending not to look at the mailbox."

He leaned back in his chair.

"Could be nothing."

Beat.

"Actually, saying that out loud made me sound insane."

He offered his hand.

"I'm Adrian."