does the horse theif cause these followers to be dicarded to the discard pile or to their places on the board?

darthmax said:

Discarded.

ok but what about mules from the purchase deck? if discarded, are they useless until the end of the game or they return to the purchase deck?

"Talisman and Purchase Cards are treated in all respects like
Adventure Cards, except that instead of being placed on a
discard pile when not needed, they are instead returned to
their appropriate deck and are available to other characters
once more." (p. 16)

...i have to read all the instruction booklets again...

:-(