From TARDIS Index File, the free Doctor Who reference.

Herrick was a member of the R1C crew under Jackson on its quest to recover the Minyan race banks from the P7E. He was captured and interrogated by Ankh and Lakh, who gave him bombs disguised as the race banks. The Doctor realised the deception, obtained the real race banks, and tricked the Guards into taking the bombs back to the Oracle. (DW: Underworld)