Hey! I've just handed in my answer, but while I was doing it I think I noticed a mistake? On the 4th line, 2nd word, it's O E M T, with the A provided for E. They key says that all R's are T's, and so everywhere there's an R, there's a T already added in. But, there isn't an R above this T, and an R wouldn't fit anyway because you need a K (as the word is 'back').

It actually very nearly went over my head, so I think that might be why it's not been noticed before now? But it did confuse me for a little while, so I thought I'd mention it :)