Mr. Moto’s Last Warning

The British Navy in Port Said is orchestrating plans for naval manoeuvres with the French fleet. These plans are delayed due to concerns of potential sabotage, prompting increased security measures and suspicion among the involved parties. The tension sets the stage for espionage and covert activities in the harbor.

Madame Delacour, wife of the French naval admiral, arrives on a ship docking in Port Said, along with her daughter Marie. Their arrival attracts the attention of spies and secret agents, as they become involved in the unfolding espionage activities. Their presence becomes central to the intelligence operations occurring nearby.

Madame Delacour and Marie are befriended by Eric Norvel, the humorous Rollo Venables, and a disguised figure claiming to be Mr. Moto. Norvel quickly reveals his true nature as a spy, leading to a series of deceptive interactions that signal the beginning of covert operations involving multiple agents.

Norvel lures Mr. Moto to his death after exposing his true identity as a fellow agent disguised as Mr. Kuroki, a curio dealer. This event highlights the treacherous world of espionage and introduces the antagonist's dangerous tactics. The real Mr. Moto remains elusive, observing the unfolding events.

Norvel takes Delacour and Venables to see Fabian the Great, a ventriloquist and gang leader of saboteurs. This gathering reveals the existence of a conspiracy to sabotage the French fleet, with Fabian and his gang plotting destruction and chaos. Secrets are exchanged, and espionage plots begin to solidify.

Fabian discovers that Danforth is actually a secret British agent named Burke. This revelation heightens the stakes, as the spy network's members are exposed, and the threat to the French fleet escalates. Spy identities are revealed, complicating the conspiracy.

Fabian lures Burke (Danforth) to the ship 'The Vulcan' and kills him by trapping him in a diving bell. The murder marks a critical turning point, demonstrating the lengths to which the saboteurs will go to achieve their goal and eliminate threats within their ranks.

Fabian suspects Mr. Kuroki might be the elusive Mr. Moto, leading to covert surveillance and following of Moto's movements. Connie, Fabian's girlfriend, unknowingly becomes involved as she follows Moto to the Port Commandant's office to gather intelligence.

Hakeem attempts to destroy Mr. Moto with a bomb, but Moto escapes, leading to a chase through a warehouse. Moto and Venables are falsely tied in sacks and thrown into the ocean but manage to escape. This sequence displays the escalating danger and action of the espionage war.

Moto frees Venables after their underwater escape and fights off saboteurs. He cleverly tricks Hawkins and seizes a sharp piece of metal during the chaos, showcasing his resourcefulness. Connie becomes distressed witnessing the violence and seeks police assistance.

Moto overpowers Norvel and diffuses the explosives intended to destroy the French fleet prematurely. He then fights Fabian, who is ultimately shot by Connie, revealing her bravery. The confrontation exposes the saboteur's plans but leaves the audience uncertain about which country was orchestrating the attack.