help understanding pattern

[uniquo]

In the garnstudio DROPS number 102-2

it says "1st row: Knit from 1st to 6th MT (= marking thread), turn.
2nd /3rd row: Knit to 5th MT, turn and knit back to the 6th MT."

I'm confused with the 3rd row. After turning, do I knit from the 35th stitch back to the 6MT and leave a gap, or do I start knitting from 1MT to reach the 6MT?

Here is what I mean

1ST ROW 1MTAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA6MT TURN
2ND ROW 6MTAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA5MT TURN AAAAAAA - 1MT Do I knit from the 1st mark thread after turning, or do I knit from the end of the 5MT after turning to start the 3rd row?

Also it states you will need to use 2 types of wool. So I should cast on 84 stitches instead of 42 sts to accomodate the extra wool?

Thanks