Shere is a chemical substance taken by a person to inhibit access to their memory by the T-probe. Shere was powerful, and it enabled restriction to memory even when the person died. This chemical got used by Miles Teg to prevent delay in his interrogation after getting captured by the Honored Matres. Because of the Shere inhibiting access to his memories for a while, Miles Teg's Atreides genes awoken in him, granting him superpowers.