When this Anomaly opened up, a Dracorex fled through from Sir William de Mornay. When the ARC team arrived, they nearly sent the Dracorex back through the Anomaly (incorrectly believing that it linked to the Dracorex's home time period), until de Mornay came through the Anomaly into the present to kill the Dracorex. The ARC subsequently locked the Anomaly.
Sarah Page had the Anomaly temporarily unlocked and travelled through to Medieval times to find out about de Mornay and the Dracorex's presence there, then returned through. After the ARC team talked de Mornay out of killing the Dracorex, he returned through the Anomaly to Medieval times. (Episode 3.7)
- Some fans believe that this Anomaly links the exact same spot in time, as William de Mornay stumbled across a tavern in present day London that also existed near the Medieval side of the Anomaly.