Sandi is joined by Zoe Lyons, Dan Tiernan, Josh Widdicombe and Alan Davies for an underground and underwater episode of QI.
| Name | Type | Role | |
|---|---|---|---|
| Sandi Toksvig | Host | Presenter | |
| Josh Widdicombe | Guest Star | Panellist | |
| Zoe Lyons | Guest Star | Panellist | |
| Dan Tiernan | Guest Star | Panellist | |
| Alan Davies | Guest Star | Panellist |