Alchemists' Elixir. Crown and Country, #4

A failed assassin is a dead assassin.or so the rules which govern the Aveneaux Assassins' Guild proclaim. As a Guild member, Aribelle L'Angier knows her mission is dangerous, but some rules were made to be broken. The risk worth the sacrifice. When her attempt to assassinate East Angelían Agency member and rumored spy, Declan Cervantes goes decidedly sideways, she is taken on a journey back to the homeland she swore never to return to again.
The longer Declan is in Aribelle's presence, the more he realizes she is far from what she seems. Objectives that should have been crystal clear blur the more is revealed of her secret agenda. A series of explosions near her looks as if her Guild might be close to exacting their revenge for her failure. Or are they?When a dead chemist she'd been sent to dispatch, resurfaces very much alive and the object of a mad man's obsession, Declan and Aribelle must race against time to find him before the secrets of his formula are revealed and it plunges East Angelía into civil war.