Appearing in "Prisoners of the Mysterious Master Mold!"
- Norton McCoy (First appearance) (Only in flashback)
- Edna McCoy (First appearance) (Only in flashback)
- Dr. Bolivar Trask
- Master Mold (First appearance)
- Sentinel MK I
- Sentinel 1/Section Leader
- Sentinel 2
- Sentinel 3
- Sentinel 3-D (First appearance)
- Sentinel 4 (First appearance)
- Sentinel 5 (First appearance)
- Sentinel 6
- Sentinel 7
- Sentinel 9
- Sentinel 11 (First appearance)
- Sentinel 17
- Sentinel A
- Sentinel B
- Sentinel C
- Sentinel L (First appearance)
- Sentinel O (First appearance)
- Sentinel T (First appearance)
Races and Species:
Synopsis for "Prisoners of the Mysterious Master Mold!"
Continued from last issue... Tracking the Sentinels back to their base to save Bolivar Trask, the X-Men are caught off guard by the base's defenses. The X-Men find the defenses too powerful and Professor X calls for a retreat. Planning another strategy, the Professor has Iceman create a glider out of ice that he and Beast will ride, followed by the Angel, in an attempt to sneak into the base. As Cyclops blasts the glider into the air with his optic blast, Hank and Bobby are soon captured and taken prisoner by coils that spring out of the defense system. Angel follows not far behind; however, he's forced to retreat when a flame thrower almost sets him ablaze.
Beast and Iceman are then sealed within a cage and gassed so that the Sentinels can examine them further. Witnessing this, Bolivar Trask denounces the Sentinels’ plans to take over humanity in order to protect them from the mutant menace. The Sentinels take Trask to their creator and the machine he invented to create his Sentinels: The massive Master Mold. Master Mold demands that Trask pledge his allegiance to him, or he will use the weapons cache that Trask had armed them with to destroy half of the United States. When Trask tells the giant robot that the X-Men will stop him, it almost gloats telling Trask that it will examine the two captured mutants and defeat the others.
Outside of the Sentinel Base, the Professor attempts a different strategy on the Sentinels. Knowing that his mental powers have some effect on the robots, he exerts all his will causing the Sentinels controlling the weapons within their base to suddenly shut down, leaving the remaining Sentinels incapable of action until they get further orders from Master Mold. As Cyclops, Angel and Marvel Girl break through the defenses to gain entry into the Sentinel Base, the Beast is brought before Master Mold. Master Mold then forces Trask to use a psycho-probe device so that the robot might learn the origins of this mutant in the hopes of learning a way to defeat them.
Meanwhile, Cyclops and the others come across a bunch of deactivated Sentinels when they are spotted by one that is still active. With no orders on how to handle the intruders, the Sentinel tells the X-Men to follow it while it goes to get more instructions. The X-Men follow in hopes that it will bring them to its leader. As Beast recounts how his mutant powers gave him an advantage as a child over schoolyard bullies, the other X-Men find Iceman. Before they are able to free Bobby, they are attacked by a team of Sentinels, which they easily defeat. They then free Iceman and continue their search for Hank and Trask.
Beast continues his tale explaining that in high school his mutant powers made him a football star, attracting the attention of Professor X. He came to Hank's parents and offered to take Hank into his school to train him in the use of his powers. Hank, by this point, has not implicated Xavier's affiliation with the X-Men; however, Master Mold decides that learning the identity of the X-Men's leader would provide him the key to destroying mutants and he probes deeper. Monitoring the situation from safety with his mental powers, Professor X sends out his astral form to try and stop Hank from outing him as the X-Men's leader. With the probe stopped, Xavier attempts to exert his mental will on Master Mold. However, the massive Sentinel detects Xavier's presence and repels his astral form with micro-electric blasts, sending a weakened Xavier to return to his body.
The X-Men continue to fight their way through the Sentinels of Master Mold. Just when they think they have defeated all threats, the X-Men are suddenly pinned to the ground by a strong gravity ray. With the X-Men defeated, Master Mold demands that Trask create an army of Sentinels for him. He refuses and Master Mold orders his minions to grab hold of Trask and prepare to force him to do Master Mold's bidding.
This story is continued next issue...
- The origin that Beast explains in this tale contradicts a later story explaining Beast's origins between X-Men #49-52 that accounts Xavier's recruiting of Beast into the X-Men following Hank's encounter with the evil Conquistador.
- Let's Hear it for These Marvel Stalwarts who'll be Working Overtime from now on to Bring these Adventures to you Monthly...
- Smilin' Stan Lee, Writer
- Jolly Jack Kirby, Designer
- Jovial Jay Gavin, Penciller
- Darlin' Dick Ayers, Inker
- Adorable Artie Simek, Letterer
- Werner Roth helped pencil this issue under the pseudonym Jay Gavin.
- It is stated in this issue that the Sentinels do not have any feelings as they are robots. However, they apparently feel Professor X's mental blast as they groan in pain.
- Professor X states there are things called "thought particles" and he bombards Beast with them.