Joshua and all Israel pretended to be defeated by them and they retreated along the way to the desert.

The land allotted to Joseph’s descendants extended from the Jordan at Jericho ¹  to the waters of Jericho to the east, through the desert and on up from Jericho into the hill country of Bethel. ² 

When the men of Ai turned around, they saw ¹  the smoke from the city ascending into the sky and were so shocked they were unable to flee in any direction. ²  In the meantime the men who were retreating to the desert turned against their pursuers.