The Time Traders by Andre Norton

The preparations for Foscar's funeral went on through the night. A wooden structure, made up of tied fagots dragged in from the woodland, grew taller beyond the big tribal camp. The constant crooning wail of the women in the tents produced a minor murmur of sound, enough to drive a man to the edge of madness. Ross had been left under guard where he could watch it all, a refinement of torture which he would earlier have believed too subtle for Ennar. Though the older men carried minor commands among the horsemen, because Ennar was the closest of blood kin among the adult males, he was in charge of the coming ceremony.

The pick of the horse herd, a roan stallion, was brought in to be picketed near Ross as sacrifice number two, and two of the hounds were in turn leashed close by. Foscar, his best weapons to hand and a red cloak lapped about him, lay waiting on a bier. Nearby squatted the tribal wizard, shaking his thunder rattle and chanting in a voice which approached a shriek. This wild activity might have been a scene lifted directly from some tape stored at the project base. It was very difficult for Ross to remember that this was reality, that he was to be one of the main actors in the coming event, with no timely aid from Operation Retrograde to snatch him to safety.