Oh, OK. After knitting those 12 heel stitches you'll turn and work across them just as for any flat knitting. You'll join everything up again later. Here's a video for How to Knit Socks: Working the Heel Flap. HTH
Happiness is catching that dropped stitch while it's still fixable..
The Following User Says Thank You to GrumpyGramma For This Useful Post: