Captain Matthews found Aspen while he was on the cruise ship called Paradise. She was only 11 years old at the time and had no memories of anything before. He took her in and raised her as his own. However, his duties as a captain of the U.S. Navy kept him away from home most of the time, but it never stopped him telling Aspen that he loves her. Aspen always calls her adoptive father "Captain," as it has become a habit.
After Aspen discovers her powers and Admiral Maylander went after her, she turned to Captain Matthews. However, Captain Matthews was not answering his phone, so she and Chance went to his house in the desert. Captain Matthews was found in his bedroom unable to move. It turns out to be a trap set by Maylander, Aspen would use her powers to break out and the three of them took off in Chance's car. When Aspendecided to go with her brother Finn, to help the Blues defend against the humans, Captain Matthews and Chance went to Mexico to lay low for awhile, and waited for Aspen to return.