Captain Joe Martin arrives in Aden with his wife Honor to replace the outgoing and much loved Captain Nick Page of the Royal Military Police.

Led by Major Harry Markham, the Royal Military Police assist Special Forces on a dangerous mission. Mary Markham experiences complications with her birth.

Captain Joe Martin meets with American journalist Martha Franklin to demand she hand over incriminating evidence. Christmas celebrations at the Royal Military Police base are cut short.

The RMP search desperately for George as the Markhams struggle to cope with his loss. Tilbrook brings Markham to see Abdul-Kadir Hakim in prison about George's kidnap.

The NLF demand a swap, their leader Hakim in return for George Markham. Alison watches over Ed in hospital. Honor confronts Martha about her relationship with Joe.

Joe faces court-martial for disobeying orders, Ed offers to represent him. Fearing for Yusra's safety from the NLF, Armstrong leaves the base to find her. Doctor Russell refuses Alison an abortion.