He has tricked his brother.
They were to join, and both fight against you, but Jaimihr tried to get the treasure out before either you or his brother came.

He is trying now, sahib!" "Miss McClean! Ask her where Miss McClean is! Ask for Miss Maklin, sahib!" "Jaimihr has told her that thou and Alwa and Mahommed Gunga are all dead, and the British overwhelmed throughout all India! He has her with him in a carriage, under guard, for all his men are with him and he could spare no great guard for his palace.

See! Look, sahib! Jaimihr's palace is in flames!" Alwa all but fell from his charger, laughing volcanically.

The Rajput, who never can agree, can always see the humor in other Rajputs' disagreement.
"Ho, but they are playing a great game with each other!" he shouted.

But Cunningham decided he had wasted time enough.