Sometimes a stitch or two falls off the needles. If they haven’t gone far, you can just pick them right back up again. If the stitch has not been worked yet, or the new stitch came undone when it was dropped, pick it up with the left needle. If the stitch has been worked and hasn’t come undone, pick it up with the right needle. Sometimes, even though wool is naturally grabby, a dropped stitch will unravel a few rows down. This looks bad, but it can be easily fixed.
HOW TO FIX DROPPED STITCHES
You can rip out your work, pick up the dropped stitch with the other stitches and re-knit, or you can fix the one dropped stitch with a crochet hook.
On the knit side of the work, insert the crochet hook into the dropped stitch from below, front to back.
Grab the lowest strand of loose yarn above the stitch ...
... and pull it through the dropped stitch. This new loop is the new stitch.
Repeat until you have hooked the last strand, and place the rescued stitch back onto the knitting needles.