King's messenger found him gone already.

Then Charles took counsel in the matter with the Chancellor.
Clarendon's habitual gravity was increased to sternness. He spoke
to the King--taking the fullest advantage of the tutelary
position in which for the last twenty-five years he had stood to
him--much as he had spoken when Charles had proposed to make
Barbara Palmer a Lady of the Queen's Bedchamber, saving that he
was now even more uncompromising. The King was not pleased with
him. But just as he had had his way, despite the Chancellor, in
that other matter, so he would have his way despite him now.
This time, however, the Chancellor took no risks. He feared too
much the consequences for Charles, and he determined to spare no
effort to avoid a scandal, and to save the already deeply-injured
Queen. So he went secretly to work to outwit the King. He made
himself the protector of those lovers, the Duke of Richmond and
Miss Stewart, with the result that one dark night, a week or two
later, the lady stole away from the Palace of White-hall, and
made her way to the Bear Tavern, at the Bridge-foot, Westminster,
where Richmond awaited her with a coach. And so, by the secret
favour of the Lord Chancellor, they stole away to Kent and
matrimony.

That was checkmate indeed to Charles who swore all manner of
things in his mortification. But it was not until some six weeks
later that he learnt by whose agency the thing had been
accomplished. He learnt it, not a doubt, from my Lady
Castlemaine.

The estrangement between her ladyship and the King, which dated