There are only 2 days left to watch Houdini & Doyle for free on FOX NOW. The last day the series will be available via the official streaming site is tomorrow, August 9. If you want to sample a single episode, I'd recommend In Manus Dei, which was my personal favorite (review here).
After the 9th, the only way to watch Houdini & Doyle will be via pay services such as Amazon and iTunes. The first season is available on DVD in the UK, but there is yet no news of a U.S. DVD release.