01/03/15 UPDATE: After so many requests I thought I would just go ahead and post the slight changes that I made to this pattern to achieve this look. Here they are,
I am really loving this pattern!

I am using my Grandmother’s hook (marked as a 6mm) but I think it is a bit smaller than that, maybe a 5.5mm, so you might want to experiment with your hook size.

I modified the pattern as follows:

UPDATED: I made this very basic photo tutorial (sry for quality) but hopefully it clears up a bit of the confusion surrounding rows 5&6. :-D

I started with a chain row of 35.

Row 1: is a Tunisian Foundation Purl Stitch (basically just pull up your loops through the little bumps on the underside of your chain.) Work Return Row.

REMEMBER:You should always have 35 loops on your hook before working return row. After working return row you should have 35 vertical bars (including the first stitch along the selvedge)

Row 2: Work Tunisian Twisted Stitch across. Work return row.

Row 3 & 4: Repeat Row 2.

Row 5:
• Chain 1, skip 1st stitch as usual AND next vertical bar,
• work Tunisian Shell Stitch in next stitch (you should have 4 loops on your hook at this point),
• skip next 2 vertical bars,
•work Tunisian Shell Stitch*
• repeat from * to last 2 stitches;
• skip next vertical bar,
• YO, insert hook through 2 loops of last stitch, YO and pull up stitch;
YO and pull through 2 loops. (Should have 35 loops on hook.)
• Work return row.

Row 6: Repeat Row 2.

Rows 7- to end (leaving enough yarn for the last 4 rows): Repeat Rows 5 and 6

Last 3 Rows: Repeat Row 2

Last Row: Tunisian Simple Stitch

Voila! Just be sure to block this to open up the stitches, it looks so much better with blocking. BTW, the diagonal that can occur is a natural byproduct of these stitches. During the blocking you can choose whether to leave the diagonal in (I kinda dig it) or take it out. :-D

Edit: Updated with corrections

Thursday, January 23, 2014: Almost complete! Just a few more rows and some blocking to straighten out the sides. So happy with this stitch and technique. Great, easy pattern!

Saturday, January 25, 2014: Complete! I used up every last little bit of this skein and the scarf is a tad over 6 feet long! Blocking with lace wires really helped open up the stitches, made the edges super crisp/straight and made Chroma even softer than it already is. I love this scarf! Time to mail it off to my surprise recipient!