What Lies Beneath was the 22nd episode and season finale of the fifth season of The Dumping Ground. It was first broadcast om 15th December 2017 at 5:00pm on CBBC and CBBC HD.
Elektra arrives at the Dumping Ground to inform everyone that Roman remains have been discovered at the site of Ashdene Ridge, derailing Peter Umbleby's plans. Elsewhere, Tyler finds a strange pattern with the other properties that Peter Umbleby has acquired.
- The end credits feature Merry Christmas Everybody by Slade, rather than the usual theme. The very end where the CBBC logo appears is also edited to feature animated snow falling.
- Christopher John-Slater makes a guest appearance as Frank, last seen in the season 3 finale Refuge.
- This is the first time Tracy has been mentioned since One For Sorrow
- This is the second time a Previously recap has been seen, after Jody in Wonderland
- This is the first time burger diving has been mentioned since Finding Frank
- Finn says,"I didn't like it last time," referring to the events of The Long Way Home