Dreams (writing as W T Quick)
1. Dreams of Flesh and Sand (1988)
2. Dreams of Gods and Men (1989)
3. Singularities (1990)

Mammoth Stone Trilogy
1. The Mammoth Stone (1993)
2. The Keeper of the Stone (1994)
3. The Last Mammoth (1995)

Roar (writing as Sean Kiernan)
1. Roar (1998)
2. Cauldron (1998)

Systems (1988) (writing as W T Quick)
Yesterday's Pawn (1989) (writing as W T Quick)
Chains of Light (1992) (writing as Quentin Thomas)
Star Control Interbellum (1995) (writing as W T Quick)
Spirits Walking Woman (1998)
Sister of the Sky (1999)

X-Files (misc. novels) (writing as Quentin Thomas)
Ascension (1997)

Planet of the Apes (writing as W T Quick)
Planet of the Apes - the Adult Novelization (2001)