If you have enough stitches on the needle, you'd knit the 25, turn the work and purl back 38. If that gets you to the end of the row, then you start working all the stitches at this point.
If, however you don't have 38 after you turn, I'd assume that there is an error in the number of stitches and I'd try just purling all the way back and taking it from there.
