There is gonna be one, but nothing is set yet. they might even backfire the whole thing! If 你 want a Spirit 2, type in `Spirit 2 petition' & click on the first link.
anyway, it should be about their life with their foal... But something bad happens. Like the humans rebuilding the railroad 或者 something.
I think Rain's and Spirit's 驹, 小马驹 will get captured and Little Creek dies, So it is up to the rest of the herd to save their 驹, 小马驹 without getting killed 或者 hurt 由 all the weapons the bad guys have.