Related Clues:
- Core, as family
- Of fission or fusion
- Not transparent or intelligible
- Not distinct in nuclear way
- Of atomic energy
- Not obvious, obscure
- Using atomic energy
- Cloudy or opaque
- These weapons release atomic energy
- Clue ran oddly to atomic
- Not transparent or free from doubt
- Ill-defined or not easily understood
- Has the North got you free of such power?
- and 19 across, it sounds like the explosive break-up of angling
- At last it's obvious that this has to do with 29 across