20 sts + 26 rows = 4" [10cm] in St st (k every st when working in the rnd; k on RS, p on WS when working flat). BE SURE TO CHECK YOUR GAUGE.
SKP (slip, knit, pass)
A decrease worked by slipping one stitch, knitting the next stitch, then passing the slipped stitch over the stitch just knit.
M1 (make 1)
An increase worked by lifting the horizontal thread lying between needles, placing it onto the left needle and working it through the back loop.
Holding the 2 needles parallel with WS of sock tog, thread a large-eyed blunt needle with yarn tail and
Insert blunt needle as if to k through the first st on the front needle and let st drop from needle.
Insert blunt needle into second st on the front needle as if to p and leave st on needle
Insert blunt needle into first st on the back needle as if to p and let st drop from needle
Insert blunt needle as if to k through second st on the back needle and leave st on needle. Rep steps 1-4 until all sts have been worked. Adjust tension as necessary.
K1, P1 Rib (worked over an even number of sts)
All Rnds *K1, p1; rep from * around.
SOCKS (make 2)
With A, cast on 40 sts. Divide sts evenly onto 4 needles. Place marker and join, being careful not to twist sts. Work in K1, P1 Rib for 3" [7.5cm]. Change to B and work in St st (k every rnd) until piece measures 6" [15cm] from beg. K across needle 1. Turn work.
Heel is worked back and forth in rows on 20 sts.
Next Row (WS) Sl 1, p 19 sts across needles 1 and 4, place sts from needles 1 and 4 onto 1 needle.
Row 1 (RS) *Sl 1, k1; rep from * across 20 heel flap sts.
Row 2 Sl 1, p19.
Rep Rows 1 and 2 for 8 more times.
Row 1 (RS) Sl 1, k11, skp, k1, turn.
Row 2 (WS) Sl 1, p5, p2tog, p1, turn.
Row 3 Sl 1, k6, skp, k1, turn.
Row 4 Sl 1, p7, p2tog, p1, turn.
Continue in this way, working 1 more st between decs until all sts on needle have been worked, ending with a WS row - 12 sts.
Knit across 12 sts of heel, pick up and k 10 sts along side of heel flap, M1 in loop between heel flap and next needle, k across instep sts on needles 2 and 3, M1 in loop between instep needle and heel flap, pick up and k 10 sts along other side of heel flap. Divide heel sts evenly between needles 1 and 4. K 1 rnd, knitting M1 sts tog with the last st on each side of the gusset.
Rnd 1 K to last 3 sts on 1st needle, skp, k1; k across sts of 2nd and 3rd needles; on 4th needle, k1, k2tog, k to end of rnd.
Rnd 2 Knit.
Rep Rnds 1 and 2 until there are 10 sts each on needles 1 and 4.
Work even in St st until foot measures 1 1/2" [4cm] less than desired length.
Dec Rnd K to last 3 sts on 1st needle, skp, k1; on 2nd needle, k1, k2tog, k remaining sts on 2nd needle; k to last 3 sts on 3rd needle, skp, k1; on 4th needle, K1, k2tog, k remaining sts on 4th needle.
Next Rnd Knit.
Rep last 2 rnds until 4 sts remain on each needle. Slip sts from needles 1 and 4 onto 1 needle and sts from needles 2 and 3 onto a 2nd needle.
Cut yarn, leaving a 15" [38 cm] tail for grafting. Graft toe. Weave in ends.