A video for this round (Round 25) is embedded under the photo tutorial.
Special stitch in round 25:
Hdcaround – insert the hook into the stitch below the dtr (=the stitch that was skipped in the previous round) from front to back and work a hdc, encompassing all loops in between within the stitch
Round 25: Ch1, [(sc, ch2, sc) into the ch2 corner space, 2 sc, hdcaround , ^ 2 sc, popcorn st, (2 sc, hdcaround) twice, 2 sc, dcbb, (2 sc, hdcaround) twice, repeat once from ^, 2 sc, popcorn st, 2 sc, hdcaround, 2sc] 4 times.
Ss into the top of the first sc of the starting corner. – 49 sts plus ch2 corner space per side