Not Deeping's best by any stretch.
It starts off pretty interesting, a WW1 vet of 40 (and up and coming engineer/ inventor) sets up home in a quiet village where he sets eyes on a rather Ophelia-type young woman living under the tyrannical shadow of her alcoholic mother. Her life is so miserable she loses the will to live and even contemplates suicide. The man decides to make it his mission to bring happiness to this somewhat limpid creature and that's "The White Gate" in a nutshell.
The first half is a solid 3 stars but it dissolved in plot after their marriage and during their honeymoon in France. YAWN.
Happily, this is available on public domain and I did not buy it.