A real treat if a little confusing. Hitchcock throws the expressionist kitchen sink of edits, lighting and special effects at this one. It's like an artist sketchbook of many filmic and plot devices he would revisit as stand alones in scenes in his later films.
In this film he barrels us around a strange old house comprising almost completely of a giant staircase. The McGuffin is a rather impressive diamond necklace. This is enough to keep us deliciously disoriented and to precipitate oblique conversations, fights, comic exchanges, chases and many mysterious rabbit-holes in the plot.
I will be easily able to watch this several times more and get new things every time.
We take nothing for granted since the truth in the story remains a movable feast.
Hitchcock has in this this film, a catalogue of story arc possibilities and he artfully lets them resurface and dissipate.
He uses a mixture of effects; under-cranked cameras, jump edits and miniatures always to distort time, space and dimensions. I thought it was great fun. The cast were up to the challenges at play and kept Number 17 a pacy and still believable confection.
IOF have a really lovely print on YouTube where sound and pictures are both very good.