Chapter 4 ends with Sakima discovering the secret identity of the Masked Marvel.  He is Jim Arnold, one of the insurance investigators.  But wait!  Here comes Jim now.  It looks like Sakima was wrong this time.  Our hero's identity is safe . . . at least for now.



Mace and another of Sakima's henchmen are stealing some plans to the storm sewers below an airplane factory.  They are going to plant a bomb to destroy the factory.  Meanwhile, two of the investigators are coming to question a shady lawyer whose office is directly above the engineering office.  The investigators discover  the villains and a fight ensues, but Mace gets away with the plans.



The investigators find a copy of the plans and decide to explore the sewers.

Four investigators and four drains.  Let's each take one and see what we can find.

One of the investigators puts on his mask and becomes the Masked Marvel.  He discovers Mace and another bad guy setting the bomb.  Naturally a fight ensues . . .



  . . . and the bomb starts ticking down to an explosion.  Mace runs out while the second villian battles the Masked Marvel.  While they continue to fight . . .

. . . . the bomb explodes!  Is this the end of the Masked Marvel?