After leaving the bulk of his treasure on Gardiner's Island, Kidd received another friendly message from Lord Bellomont, and was by now persuaded that he could go to Boston without danger. With his wife on board his sloop, and she stood by him staunchly, he laid a course around Cape Cod and made port on the first day of July. Captain and Mrs. William Kidd found lodgings in the house of their friend, Duncan Campbell, and he walked unmolested for a week, passing some of the time in the Blue Anchor tavern. "Being a very resolute fellow," wrote Hutchinson, "when the officer arrested him in his lodgings, he attempted to draw his sword, but a young gentleman who accompanied the officer, laying hold of his arm, prevented him and he submitted."

In the letters of Lord Bellomont to the Lords of Plantations and Colonies are fully related the particulars of Kidd's downfall and of the finding of his treasure. On July 26th, he stated:

"My Lords:

"I gave your Lordships a short account of my taking Capt. Kidd in my letter of the 8th. Inst. I shall in this letter confine myself wholly to an account of my proceedings with him. On the 13th, of last month Mr. Emmot, a lawyer of N. York came to me late at night and told me he came from Capt. Kidd who was on the Coast with a Sloop, but would not tell me where; that Kidd had brought 60 pounds weight of gold, about 100 weight of silver, and 17 bales of East India goods (which was less by 24 bales than we have since got out of the sloop). That Kidd had left behind him a great Ship near the coast of Hispaniola that nobody but himself could find out, on board whereof there were in bale goods, saltpetre, and other things to the value of at least 30,000 pounds. That if I would give him a pardon, he would bring in the sloop and goods hither and fetch his great ship and goods afterwards.

"Mr. Emmot delivered me that night two French passes which Kidd took on board the two Moors' ships which were taken by him in the seas of India (or as he alleged by his men against his will). One of the passes wants a date in the original as in the copy I sent your Lordships, and they go (No. 1) and (No. 2). On the said 19th. of June as I sat in Council I wrote a letter to Capt. Kidd and showed it to the Council, and they approving of it I despatched Mr. Campbell again to Kidd with my said letter, a copy whereof goes (No. 4). Your Lordships may observe that the promise I made Capt. Kidd in my said letter of a kind reception and procuring the King's pardon for him, is conditional, that is, provided he were as Innocent as he pretended to be. But I quickly found sufficient cause to suspect him very guilty, by the many lies and contradictions he told me.

"I was so much upon my guard with Kidd that he arriving here on Saturday of this month, I would not see him but before witnesses; nor have I ever seen him but in Council twice or thrice that we examined him, and the day he was taken up by the Constable. It happened to be by the door of my Lodging, and he rush'd in and came rushing to me, the Constable after him. I had him not seiz'd till Thursday, the 6th Inst. for I had a mind to discover where he had left the great Ship, and I thought myself secure enough from his running away because I took care not to give him the least umbrage or design of seizing him. Nor had I till that day (that I produced my orders from Court for apprehending) communicated them to anybody and I found it necessary to show my order to the Council to animate them to join heartily with me in securing Kidd and examining his affairs nicely,[[4]] ... discover what we could of his behaviour in his whole voyage. Another reason why I took him up no sooner was that he had brought his wife and children hither in his Sloop with him who I believ'd he would not easily forsake.

"He being examined twice or thrice by me and the Council, and also some of his men, I observed he seemed much disturbed, and the last time we examined him I fancied he looked as if he were upon the wing and resolved to run away. And the Gentlemen of the Council had some of them the same thought with mine, so that I took their consent in seizing and committing him. But the officers appointed to seize his men were so careless as to let three or four of his men escape which troubled me the more because they were old N. York Pyrates. The next thing the Council and I did was to appoint a Committee of trusty persons to search for the goods and treasure brought by Kidd and to secure what they should find till the King's pleasure should be known as to the disposition thereof, as my orders from Mr. Secretary Vernon import. The said Committee were made up of two Gentlemen of the Council, two merchants, and the Deputy Collector, whose names are to the enclosed Inventory of the goods and treasure.

"They searched Kidd's lodgings and found hid and made up in two sea beds a bag of gold dust and Ingots of the value of about 1000 pounds and a bag of silver, part money and part pieces and piggs of silver, value as set down in the said Inventory. In the above bag of gold were several little bags of gold; all particulars are very justly and exactly set down in the Inventory. For my part I have meddled with no matter of thing under the management of the Council, and into the Custody of the aforementioned Committee, that I might be free from the suspicion and censure of the world.

"The enamel'd box mentioned in the beginning of the Inventory is that which Kidd made a present of to my wife by Mr. Campbell, which I delivered in Council to the said Committee to keep with the rest of the treasure. There was in it a stone ring which we take to be a Bristol stone. If it was true[[5]] it would be worth about 40 pounds, and there was a small stone unset which we believe is also counterfeit, and a sort of a Locket with four sparks which seem to be right diamonds: for there's nobody that understands Jewels[[6]] ... box and all that's in it were right, they cannot be worth above 60 pounds.

"Your Lordships will see in the middle of the Inventory a parcel of treasure and Jewels delivered up by Mr. Gardiner of Gardiner's Island in the province of New York and at the East end of Nassau Island, the recovery and saving of which treasure is owing to my own care and quickness. I heard by the greatest accident in the world the day Capt. Kidd was committed, that a man... offered 30 pounds for a sloop to carry him to Gardiner's Island, and Kidd having owned to burying some gold on that Island (though he never mentioned to us any jewels nor do I believe he would have own'd to the gold there but that he thought he should himself be sent for it), I privately posted away a messenger to Mr. Gardiner in the King's name to come forthwith and deliver up such treasure as Kidd or any of his crew had lodg'd with him, acquainting him that I had committed Kidd to Gaol as I was ordered to do by the King.