After a Paris operation fails on her watch, Central Intelligence Agency interrogation officer Alice Racine works undercover at a community centre in London.

Racine's former station chief and mentor Eric Lasch tells her she should not feel guilty for the Paris deaths and needs to get back into the field.

The CIA and MI5 learn that radical imam Yazid Khaleel plans a biological attack on an American target on British soil in collaboration with American-born Islamic convert David Mercer.

Frank Sutter, an officer from the CIA's London Station, tells Racine she has orders from Europe Division Chief Bob Hunter to help them interrogate and break Khaleel's captured courier, Lateef.

Romley's team track the bullets used in the killing of their men who apprehended Lateef to an AT308C sniper rifle, which is revealed to have been checked out of a Metropolitan Police armoury by corrupt MI5 operative John Wilson.

As Mercer is about to meet with a contact in Prague, Racine cuts a deep incision into his groin, opening his femoral artery, killing him.

The site's critical consensus states, "Unlocked strands an all-star cast in a spy thriller whose embrace of old-school formula might be refreshing if it weren't bogged down in genre clichés and a predictable plot.

[12] Guy Lodge of Variety was not impressed with the film and wrote, "Years on from The Girl With the Dragon Tattoo, Noomi Rapace is still ready for action, though this middling thriller lags behind her.

"[3] Stephen Dalton of The Hollywood Reporter called it a "functional contemporary spy yarn" that is "played way too straight" and "brings nothing fresh to the formula besides the minor innovation of dropping an action heroine into a male-dominated field".