With a scientific mind and a lethal mastery of martial arts, Bobbi Morse has always been one of S.H.I.E.L.D.'s best agents, but now she's going solo! When someone close to her is murdered, Bobbi discovers some strange goings-on in the peacekeeping organization's own medical-and-recovery network. But when Lance Hunter's undercover gig at the London Hellfire Club goes south, Mockingbird sets off, battle staves at the ready, to save Hunter--and the Queen of England! From helping out a teen driven bonkers by her own new powers, to doing a little dog-sitting, Bobbi shows she's a woman of many talents!

Contains material originally published in single magazine form as Mockingbird: S.H.I.E.L.D. 50th anniversary #1 and Mockingbird #1-5.