Keith Laumer 
Time Trap 

ABE LINCOLN IN AFRICA?He was seen – and photographed – in a Tunisian bazaar. And an ancient Spanish galleon, fully crewed with ancient Spaniard, was taken in tow off Tampa by the Coast Guard…and a few luckless people found themselves living the same day over and over and over…Something was badly wrong with Time – but Roger Tyson didn’t know it until he met the lovely agent from elsewhen and started on a mad chase through the dimensions, plagued by a motley bunch of temporal castaways, and pursued hotly by Oob the Rhox!