Third Wife by Lisa Jewell

In the early hours of an April morning, Maya stumbles into the path of an oncoming bus.
A tragic accident? Or suicide? Her grief-stricken husband, Adrian, is determined to find out.

Maya had a job she enjoyed; she had friends. They'd been in love. She even got on with his two previous wives and their children. In fact, they'd all been one big happy family.

But before long Adrian starts to identify the dark cracks in his perfect life.
Because everyone has secrets. And secrets have consequences. Some of which can be devastating.