Ellie reveals that she coated the red marker on the desk with ultraviolet powder that will glow under the black lights at the dance, and whoever used the marker to destroy Mr. Larkin’s poster will be caught green-handed. Ellies makes a playful show of checking both Tripp’s and Brynn’s hands, which are clean. Ellie then tries to dance with Shane and Charlotte to check their hands. Shane’s hands are clean, but she can’t get close enough to check Charlotte’s before she chases her off. Tripp then notices that Mason’s hands are glowing, indicating he vandalized the picture.

Once Brynn sees Mason’s glowing hands, she realizes why Lila Robbins’ photograph looked so familiar: it’s a much younger version of Mason’s mom, Ms. Rafferty. This means that Mason must really be Mr. Larkin’s brother. Brynn confronts Mason about this in the auditorium, where she believes they are alone. She promises not to tell anyone—Mason explains that his father, Dexter, was abusive, and they ran away for their own safety. Mr. Solomon actually was a friend of Lila and her father, so he helped them move to Sturgis. This is why Mr. Solomon disliked Dexter and Mr. Larkin.

Mr. Larkin did tell Mason that he was his brother, shortly before he died.