The Black Ambulance is the fourth episode of Metal Cardbot, and the episode where Mega Ambler is sealed.

Plot

At school, Teo and Lavi discuss rumors of a mysterious “black ambulance” driven by the Grim Reaper that kidnaps children. While Anna is scared by the rumors, Vera and Jun dismiss them as made-up stories. Later that day, Teo is struck by a stray tire rolling down the street and knocked unconscious, with Anna witnessing him being kidnapped by the “black ambulance”. He wakes up in a warehouse with Mega Ambler, who introduces himself as an unlicensed traveling doctor from planet Machina, begins diagnosing and bandaging Teo to treat him. Before being completely wrapped up in bandages, Teo manages to send his location to Jun.

At Edo‘s repair shop, Edo conducts maintenance checkups on Blue Cop and Mega Trucker, warning Mega Trucker about a worn-out damper in his knee. When Anna rushes in reporting Teo’s kidnapping, Jun heads out with Blue Cop to rescue him. Confronting Mega Ambler, Blue Cop warns Jun of the doctor’s rogue reputation. Jun summons Mega Trucker into battle, but Mega Ambler is able to analyze his weaknesses and target his faulty knee, taking him out of the fight. Blue Cop steps in, but takes heavy damage in his arm from Mega Ambler’s Forceps Shock. However, Jun devises a plan to use his limp arm as a weapon, allowing Mega Ambler to be sealed.

Back at the workshop, Edo repairs both Blue Cop and Mega Ambler, cleaning off the ambulance’s blackened exterior. With Blue Cop’s permission, Jun reveals the secret of the Metal Cardbots to Teo, who promises to keep their existence safe from the public.