Tensions rise between Luke and Henry when Anthony gets in trouble at school; Luke and Helen panic when Anthony vanishes.

After two years, witnesses come forward claiming to have seen Anthony; Henry is still obsessed by the Paulownia Tomentosa leaf; Susan and Charles make a discovery in the park.

Luke and Helen search for suspects connected to Henry's former work; Helen is desperate for information about her son; Henry continues his own investigation on the side; Catherine finds a source of comfort.

Susan and Charles focus on one suspect; stuck in the hospital, Henry seeks advice from Catherine's patient; a new discovery in the investigation.

Henry asks Fred for help; Luke and Helen still believe their son's disappearance is related to Henry's past; Catherine is troubled by Fred's death; Susan makes an important discovery.

The police and the Sullivans race to find Anthony.