Continuation from the end of Primeval New World. The fallout of the events of Sound of Thunder echo across the timeline. What has changed? Who has changed? Who will change? With the creatures and characters from the Future is Wild and Primeval added in for good measure. Cross posted as Echoes of Thunder.

Phineas, Ferb and their friends travel to 200 million years in the future to make a civilization of the Squibbons in the Northern Forest. Meanwhile, Perry goes with Dr. Doofenshmirtz to see his own created civilization of the Squibbons.

Two weeks after the first adventure in the future, Phineas and Ferb planned on an expedition to the 5 million years in the future. Meanwhile, Perry and Norm become members of the crew of Dr. Doofenshmirtz to help him have a father-daughter time with Vanessa.

Phineas and Ferb created the Time Machine 2.0 and go on an adventure into the one hundred million years in the future with their friends. Meanwhile, Dr. Doofenshmirtz and Perry are having a great time with one another in the same time with the kids.

Readers don't need to know much about the Future is Wild. The Vampyrum Spectrum and other jungle bats face a new danger: a bigger badder predatory bat that's slowly wiping out colonies. What could possibly be done to stop it? R&R!