A customer wants to move a box across a 4×4 minefield. The minefield is at a distance from where the customer is located hence, the customer has hired a chain of Messengers and an Executor to carry out this task. However, the Messengers have no idea which squares of the minefield have mines; only the customer has that information. Moreover, the Messengers cannot talk to each other and must only use sign language to transmit messages to the Executor at the end of the chain. The challenge is to safely move the box across the minefield without stepping on a mine.