Without letting anybody else know, each person must choose two other people in the room. Tell them that the first person they chose is a bomb and the second person is a shield. On a signal everybody starts moving around the room with the aim of staying as far away from the bomb as possible and keeping the shield between him or her and the bomb! You can give a signal to freeze at any moment to check whether they are doing it correctly. The group will probably end up spread out, so as a contrast, you could also play Noses (see my book for this).
Come back for a new Game next week!