bits and pieces
For some time "The Dark Tower" had been under some scrutiny as to whether it was actually written by Lewis. But I think for many who have read much of his other works have little doubt as to its authenticity.
The Dark Tower is an incomplete story; either it was never finished, or parts of the manuscript were lost. It is an entertaining read about Ransom, who is the main character of the space trilogy. This story however focuses on time travel and of course a fight between good and evil.
The other stories in this collection are also worth reading as well. Walter Hooper writes the introduction giving many insights, which are worth taking note of.
All in all it is an interesting read, but doesn't compare to rest of Lewis.