I don't know what our fascination is with twins, but there sure are a lot of books out there featuring twins, and I have some to recommend if you're in the mood.

Discussed:

Grim Reaper's Guide to Cheating Death -- Maxie Dara

A Rather Peculiar Poisoning -- Chrystal Schleyer

The Seven Miracles of Beatrix Holland -- Rachel Herron

High Season -- Katie Bishop

The Forgotten Girls -- Sara Blaedel

Blood on Her Tongue -- Joanna van Veen

Keepers of Metsan Valo -- Wendy Webb

Dying to Meet You -- Sarina Bowen

The New Neighbor -- Carter Wilson

What Blooms From Dust -- J.H. Markert

Missing Sister -- Joshilyn Jackson

Once There Were Wolves -- Charlotte McConaghy

The Good Sister -- Sally Hepworth

Also mentioned:

The Secret History -- Donna Tartt

Poisonwood Bible -- Barbara Kingsolver

The Prince of Tides -- Pat Conroy

The Thirteenth Tale -- Diane Setterfield

The Dragonlance Chronicles -- Margaret Weis & Tracy Hickman

I'll Give You the Sun -- Jandy Nelson

I Know This Much Is True -- Wally Lamb

In the Woods -- Tana French

Memory Keeper's Daughter -- Kim Edwards

Vanishing Half -- Britt Bennett

The God of Small Things -- Arundhati Roy

Flowers in the Attic -- V.C. Andrews

Game of Thrones -- George R.R. Martin