Have just added another book from 1940s Canadian paperback publisher Bell Features and Publishing to the collection. The series is not numbered but there are only 17 titles known. This is my sixteenth.
Like the other books in the series Heart in Chains is digest sized (18mmx14mm) and 96 pages of very small type. It is a paperback original. The author is Dorothy Leona Edgar, about whom nothing is known. She did write one other novel, The Strange Loves of Vickie Saunders. She may have been the wife of another writer Keith Edgar who had two books published by Bell.
The story "is a dramatically drawn picture of a sinister woman who spun a web of deceit, little caring of the hearts that were trapped therein."