Mortyr II is set during World War II and follows British intelligence officer Sven Mortyr, who is sent to his Nordic homeland to investigate rumours of a Nazi super-weapon. Sven is horrified to find his own father has been forced to work on the unit, and must thus use all his covert skills to infiltrate the Nazi stronghold and prevent the completion of the weapon and rescue his father.

Facing defeat, the Nazi forces assemble a covert team of scientists and engineers tasked with designing and building new weaponry. Now you must step into the shoes of Sven Mortyr--a British Intelligence officer on a mission to thwart the Nazis' plans and rescue his own father.