ERRATA:
The chart only shows the middle 20 of the 26 sts. So for 3 sts on either side of the chart, knit both green rows, and the first black row, and purl the 2nd black row. (It’s kind of the basic illusion background, with the black sts raised, and the green ones lying flat.)

This is a gauntlet with the Dark Mark (a symbol of evil from the Harry Potter series) shadow-knit on the inside. It’s the left arm only, as that is the appropriate placement for the Mark. If you want to make a (plain) right arm, you’re welcome to, but you’re on your own for switching the thumb around to the other side. I might make a match for it in the future, but not any time soon.

There is a chart, linked to from the pattern.