Magpie by Elizabeth Day

Marisa and Jake are a perfect couple, and Kate, their new lodger, is the perfect roommate--and not just because her rent payments will give them the income they need to start trying for a baby. Except no one is perfect. Sure, Kate doesn’t seem to care much about personal boundaries and can occasionally seem overly familiar with Jake, but Marisa doesn’t let it concern her. Kate will soon be gone, and it will just be her, Jake, and their future baby.

Conceiving a baby is easier said than done, though, and Jake and Marisa’s perfect relationship is put to the test through months of fertility treatments and false starts. To make matters worse, Kate’s boundary-pushing turns into an all-out obsession--with Jake, with Marisa, and with their future child. Who is this woman? Why does she seem to know everything about Marisa and Jake?

In her quest to find out who Kate really is, Marisa might destroy everything she’s worked so hard to create: her perfect romance, her perfect family, and her perfect self. Jake doesn’t know the half of what Marisa has created and what she stands to lose. Magpie is a tense and twisting novel about mothers and children, envy and possession, and the dangers of getting everything you’ve ever dreamed of.