Mike Lewis is a twelve-year-old train fanatic. When his mother asks him to babysit his six-year-old autistic brother Orry for the day, he discovers that Orry shares his fascination with trains. The brothers bond over their shared interest.
He Is Your Brother contains examples of:
- Bad Mood Retreat: When something upsets Orry, which happens often, he hides in the closet under the attic stairs.
- Big Brother Instinct: Mike tells off his friend Jock whenever he insults or makes fun of Orry.
- Commonality Connection: Mike's ten-year-old sister Jane points out that he's a lot like Orry, but less so - not only are they both interested in trains, but Mike often needs to go off and be by himself, the way Orry retreats into his closet.
- Married to the Job: Mr Lewis is a celebrated cellist who spends weeks or months on tour. When he is at home, he's more interested in rehearsing than in paying attention to his kids.
- Only Known by Their Nickname: Orry's real name is Lawrence, but he goes by Orry because that's what he can pronounce.
- Potty Failure: The first day Mike babysits Orry, Mrs Lewis packs him two changes of pants, just in case. Sure enough, Orry wanders off from Mike and Jock at a factory, climbs onto a wobbly stack of boxes, and is so frightened by the movement of the boxes that he wets himself.
- Rail Enthusiast: Mike has a huge collection of old train and railway pieces, including nuts and bolts, tickets, uniform buttons, signal flags, and a coal shovel. During his free time, he wanders by the railways to collect more treasures and memorizes timetables. He is endlessly fascinated by railway history and is delighted when Mr Lewis brings home a copy of History of the Canterbury and Whitstable Railway, which has been out of print for years. Orry loves riding the train with Mike and looking at Mike's collection.
- Third-Person Person: Trouble with pronouns is one of Orry's speech difficulties. He usually refers to himself by name.
- Title Drop: When Mrs Lewis tells Mike to babysit Orry at the beginning of the book, she says, "He is your brother."
