All the Spark Files books in order:
Book 1: Space Race (1998)
Book 2: Chop and Change (1998)
Book 3: Shock Tactics (1998)
Book 4: Bat and Bell (1998)
Book 5: Dog Run (1999)
Book 6: Dark Forces (1999)
Book 7: Light and Wrong (1999)
Book 8: Magical Magnets (1999)