Raintree Fusion; Raintree Fusion: Life Science Books in Order
2 books by Lisa Trumbauer. Reading level: Grades 3.2–3.7. Middle Grades (Ages 9–12).
Series books grow with readers — but that's also the trap. Most series start at one reading level and one content intensity and drift upward over the course of the run. Raintree Fusion; Raintree Fusion: Life Science (2 books by Lisa Trumbauer) lands at reading level Grades 3.2–3.7, with average content intensity 1/5. Intensity stays consistent across the series — a kid who can handle the first book can generally handle the rest.
The reading-order table below lists every book with per-volume reading level and intensity badges so you can spot any escalation before it catches your reader off guard. For a deeper dive into how we score text difficulty vs. emotional weight separately — and why series readers especially benefit from that split — see our methodology page.
Content Intensity Across the Series
ConsistentContent stays at a steady intensity level throughout the series.
Raintree Fusion; Raintree Fusion: Life Science Reading Order
| # | Title | Reading Level | Content |
|---|---|---|---|
| 1 | Body Warriors: The Immune System (Raintree Fusion: Life Science) Lisa Trumbauer | Level 3-4 | Gentle |
| 2 | Safari Adventure (Raintree Fusion: Life Science) Deborah Underwood | Level 3-4 | Gentle |
All Raintree Fusion; Raintree Fusion: Life Science Books
Body Warriors: The Immune System (Raintree Fusion: Life Science)
Lisa Trumbauer
Body Warriors: The Immune System (Raintree Fusion: Life Science)
Lisa Trumbauer
Safari Adventure (Raintree Fusion: Life Science)
Deborah Underwood
Safari Adventure (Raintree Fusion: Life Science)
Deborah Underwood
Questions about the Raintree Fusion; Raintree Fusion: Life Science series
- What reading level is the Raintree Fusion; Raintree Fusion: Life Science series?
- The Raintree Fusion; Raintree Fusion: Life Science series by Lisa Trumbauer is at a Grades 3.2–3.7 reading level (average Grade 3.5). Intended for Middle Grades (Ages 9–12). There are 2 books in the series.
- What order should I read the Raintree Fusion; Raintree Fusion: Life Science books?
- The reading-order table above lists all 2 books with per-volume reading level and intensity ratings. Start with book 1 and read in publication order unless the table indicates a different recommended order for newer readers.
- What age is the Raintree Fusion; Raintree Fusion: Life Science series appropriate for?
- The Raintree Fusion; Raintree Fusion: Life Science series is recommended for Middle Grades (Ages 9–12). The average content intensity is 1/5. Check the intensity trajectory above to see whether content gets heavier across the series — if it does, sensitive readers may want to stop earlier in the run.