I am using Groton and May's "38 Latin Stories to accompany Wheelock's" and am wondering about the following sentence which appears in the story for Wheelock's Ch. 15:
Istum inveniam et, si potero, meis viribus vincam.
my translation of this is
This one I will find and, if I am able, by my strength, will overcome.
the form meis viribus is what I am wondering about. viribus is the ablative plural. Is this one ...