The first 27 rows you worked on the outside of your sock, the rs. By pulling the sock/tube through the needles you have turned it inside out and are now working on the inside/ws of the sock. This is no different than when you are knitting flat and turn the piece over from the front side/rs to the back side/ws.
You will contnue to work the sts from the left needle to the right needle.
In order to close the small hole created by turning things inside out, you need to wrap the last stitch of row 27 (which is now the 1st st on your right needle. You need to slip this st from the right needle to the left, wrap the yarn around it then slip the st back to the right needle. Now knit just like like normal off of the left needle.