This Enemy Town by Marcia Talley

Hannah Ives is always ready to support others like herself who have been through the gauntlet of fear and uncertainty that a diagnosis of cancer often brings. So when friend and fellow survivor Dorothy Hart asks for help building sets for the Naval Academy's upcoming production of Sweeney Todd, Hannah readily agrees.

But it means associating with an old foe -- a vindictive officer whose accusations once nearly destroyed Hannah's home life. And when one corpse too many appears during a dress rehearsal of the dark and bloody musical, Hannah finds herself accused of murder -- and enmeshed in a web of treachery and deception that rivals the one that damned the "Demon Barber."

Caught up in a drama as sinister as any that has ever unfolded on stage, Hannah stands to lose everything unless she unmasks a killer before the final curtain falls ...