On We Go by Mike Gayle

A tragic loss. A chance to reconnect. And a summer they'll never forget. When Cal loses his beloved wife Nikki, and his teenage step-daughter Zoe moves out to live with her father, his whole world falls apart. But life works in mysterious ways. And when a prestigious university wants to pay tribute to Nikki with a posthumous award in Zurich, Cal sees an opportunity to both honour his wife, and mend things with Zoe. The plan is a European inter-railing trip to Zurich – but what Cal hasn't anticipated is Zoe lying to her father about it, and inviting their other relatives to join too. What starts off as a very awkward family reunion quickly takes a turn as tempers fray, secrets are revealed, and the pent-up grief they're all still carrying is unleashed.