Wilda retired from the Temporal Agents for an excellent reason.

Retired Temporal Agent Wilda Firestone just wanted to run her Toronto shop: garb Time Tourists and send them on their merry way into the past. She's content with her cat, sarcasm, and whiskey. All of that changes when a deathly ill Time Traveller literally falls at her doorstep, setting off a chain reaction which forces her to return to the job she'd retired from decades before.

The Agency sends her and her assistant, Mattea, back into three dangerous historical eras to find the disease threatening the life of every Time Traveller. They search a teeming desert bazaar in the luxurious court of Mansa Musa. They explore the dark forests of pre-Columbian North America. They get entangled in the convoluted politics of twelfth century Norse-ruled Orkney while sifting through the horrific carnage of a murdered village.

If Wilda can't return in time with the right pathogen, modern scientists can't synthesize a cure before all the Travellers fall ill. She must return to the present or lose herself in the depths of her own purposely-forgotten past.