Department Z must face a mysterious international organisation that has suddenly gained power and infiltrated the governments of several key global powers. It is believed to be responsible for past catastrophic global events and is planting the seeds of anarchy once again.

Loftus, with Gordon Craigie and his department, are determined to stop this sinister organisation, but Department Z is pushed to its limit attempting to block its destructive path. Gordon must learn to work in alignment with other international organisations so that, together, they might unearth the mystery of The Ring… but will their cooperation be enough? Can Department Z discover the truth behind The Ring before it’s too late?

Murder Must Wait is the 12th book in the Department Z series, and was originally published in 1939.