Threshold (with Janet Morris)
1. Threshold (1990)
2. Trust Territory (1992)
3. The Stalk (1993)

The 40-Minute War (1984) (with Janet Morris)
Medusa (1986) (with Janet Morris)
Outpassage (1988) (with Janet Morris)
Hawkeye (1991) (writing as Daniel Stryker)
Cobra (1991) (writing as Daniel Stryker)

Thieves' World (with Janet Morris)
City at the Edge of Time (1988)
Tempus Unbound (1989)
Storm Seed (1990)