Notes: As all fifth parts in the magazine to date, the subtitle of this story is actually included in the strip, as opposed to merely being suggested by the "Next Week" advertisement in the previous issue.
Synopsis: Two laboratory assistants are mucking about with a device that can transport objects to the past. They try to enlist the aid of a professor in perfecting the device such that it can not just send objects to the past, but retrieve them, as well.
He refuses, warning them that history can't be meddled with.
Disbelieving the professor, they press on. They send a camera back through time with the aim of getting a "perfect record of the past". It goes all the way back to a time ostensibly before dinosaurs walked the earth. The camera arrives on scene to inadvertently strike and kill the first bipedal creature as it emerges to walk on land.
When they retrieve the camera, the two lab assistants congratulate each other on their cleverness, without realizing that they have so disturbed the evolutionary cycle, they themselves are no longer human—no longer even mammalian—but some relative of the dinosaurs. In this changed reality, humans apparently never evolved.
Notes: This is an uncredited reprint of "Those Who Change" by Stan Lee and Steve Ditko.