A skinny scientist creates a machine capable of granting super strenght. His lab is broken into by a petty thief on the day before the first strength ray test. The criminal activates the machine by mistake and is hit by the strength ray, being instantly transformed in a huge hulk creature. Scared to death, he breaks the lab and escapes.

Later, the scientist finds out his lab partially destroyed. He decides to use the machine anyway. With the energy from the machine already partially depleted, the effects of the strength ray are not so extreme.

Tanker is a huge hulk, but his enemy is almost twice as big, and therefore called Double.