Books four through seven of A. G. Hayes' multi-award-winning seven-book Koski and Falk thriller set including (4) THE CHEMICAL FACTOR; (5) FINDING KATE; (6) QUANTUM DEATH (with Raymond Gaynor); and (7) THE SOLAR TRIANGLE. Complete and unabridged. Books one through three including (1) WHO'S KILLING ALL THE LAWYERS?; (2) THE JUDAS LIST and (3) IMMINENT DANGER appear in A. G. Hayes' THE COMPLETE KOSKI & FALK VOLUME I, again, complete and unabridged.