Tony Mack

 was the father of Ambrose Northover, the father-in-law of her husband, and thus the grandfather of Elliot Northover.

He, along with Dr. Nasreen Chaudhry were digging in Cwmtaff and aiming to dig further than anyone had before. After the Doctor arrived, it became apparent something was wrong, and it was soon discovered that the Silurians were digging upwards to the surface. As they were preparing for an attack, he kissed Nasreen, apparently expressing a previously unstated affection. He saved his daughter from a Silurian attack, but as a result, was injured himself by a poison dart from the Silurian's tongue which left him with a green, veiny system on his shoulder.