Mathias located Sam, as well as encountered Lara Croft at the same campsite. Tending to her injuries and listening to her stories of Sun Queen and the Stormguard, Mathias realized that she was a descendant of the Sun Queen and the key to her reincarnation, and his escape. As Lara fell asleep at the campsite, Mathias kidnapped Sam and took her to the Solarii base. Later, once Lara had recovered Sam, he killed Conrad Roth, Lara's mentor and father figure. Upon the second kidnapping of Sam, he played James Whitman's ego against him to distract a pair of Oni, allowing him to slip into the Monastery with Sam, and ultimately causing Whitman's death. There, he started to perform the ritual to swap her soul with the Sun Queen, believing that the ritual was the key for him to escape the island.