The prophecy is moving fast
Chevalier Tialys and Lady Salmakia are eavesdropping at The Consistorial Court of Discipline. The president and Brother Jasper gather round the alethiometer. It is able to describe where Lyra is but not reveal the exact location as it is not known on any map.
They are also aware of Will. They must act fast. The president dispatches Brother Jasper and the army to track down Mrs Coulter’s cave and destroy Lyra.