A quest to capture a legendary Abnormal in Bolivia leaves Will and Magnus injured and trapped in a cave-in, where they confront truths about themselves and their relationship. Henry records video letters to a special someone while working on an invention.

With the new Abnormal Homeland now openly under threat, Henry and Tesla learn that the SCIU weaponized Tesla's work to use against Abnormals. Bigfoot and Kate investigate Caleb's rise to power while Will and Abby look into Magnus' past.