| Answer | Crossword Clue |
|---|---|
| PLUMB | Delve deeply |
| RESEARCH | Delve deeply into |
| DIG | Delve. |
| PROBE | Delve |
| DIGDEEP | Delve |
| INTO | Delve ... |
| MINE | Delve |
| PORE | Delve into |
| REDIG | Delve again |
| PROBE | Delve into |
| INTO | Delve .. (investigate) |
| DIG | Delve (into) |
| EXPLORE | Delve into |
| SEEK | Delve into |
| PRY | Delve (into) |
| NTSB | It may delve into a derailment: Abbr. |
