From the pattern:

An elegant, airy stitch pattern and lacy border have fan-tastic appeal in this heirloom-worthy afghan. Stitch the squares one by one and crochet them together later.

Squares are fan shaped and a bit off-kilter to form a swirled effect when joined together.

Gauge: Rows 1 and 2=1.5”

Was on Episode 501 on Interweave. Available as eBook with other patterns at Interweave. EBook calls knitting only, but there are also crochet patterns included.