The Trager family who adopted Kyle is a typical one, and neither dad Stephen (Thomas), sister Lori (Matson) nor son Josh (Jean-Luc Bilodeau) is at all happy when mom Nicole (MacIntyre) brings home one of her "head cases." She's a social worker and believes Kyle needs a home environment to bring him out of his shell. Soon the family starts to see that Kyle has some unique abilities and an uncanny way of completing two hour IQ tests in 5 minutes with perfect scores. He encounters everyday activities such as video games, drawing and music with a wide-eyed wonder and a thirst for more knowledge. He also starts to grow fond of the Trager family and even rescues Lori from a high school party that gets dangerously out of hand. By the end of the episode, the family has accepted the strange young man, and he's learned to speak.
Kyle learns bits and pieces that may lead him to discover his identity, and he also learns life lessons as he finds a place in the family. However, when he learns that his search to discover who he is may put the Trager family in danger, he pushes his abilities to the limit, in "Overheard", in an effort to protect them. The season culminates in the finale "Endgame", in which Kyle finds answers and an ally. Unfortunately, it's at the cost of leaving behind everyone's he's come to love.