We finish the week with The Independent’s cryptic:
There’s a charade at play here.
The straight part of the clue is ‘not propitious?’ (or not likely to succeed, in other words).
The answer is BLACK (in the sense of without hope — ‘the future looked black’, eg).
Some cryptic clues want us to take a single letter from a word, as in the ‘b’ from ‘book’ in this case.
Combine this with ‘lack’, a synonym for ‘shortage’, and we get the full answer.