Wilf first encountered the Doctor on Christmas Day 2007, when the Time Lord beamed down from the Titanic with Astrid Peth. A year later, during the Adipose affair, he was to see the Doctor again – this time through his telescope as the TARDIS, with Donna aboard, sped across the sky. A keen astronomer, Wilf readily accepted the Doctor's alien nature, along with his granddaughter’s travelling in time and space. When Donna's mind had to be wiped of her travels with the Doctor, he was heartbroken but promised to keep watching the skies for the TARDIS. Extraordinarily loyal, he urged the Doctor to kill the Master and save the world when he opened the timelock on the Time War. It was Wilf who would eventually knock four times, and herald theTenth Doctor’s regeneration.