The pattern is available here after you join TKGA.org for $35 per year, possibly the best deal in the knitting world.

I’ve been wanting to do another Celtic design in cables, and this sweater is the result, which turned out to be quite a bit harder than I had anticipated. As I worked on the design, I found I needed to incorporate more and more types of crossovers, so I ended up with a wide range—from 2-stitch to 6-stitch, including some 2-over-2-over-2 crossovers. Throughout the design process as well as the knitting process, I realized this was quite a challenge, so the name became Celtic Challenge.