George Nicholas specifies the charges against Gov. Jefferson

George Nicholas to TJ, July 31, 1781: “By the resolution of the House of Delegates an enquiry is to be made into the conduct of the executive for the last twelve months. No particular instance of misconduct was specified. They seemed to think and I am still of opinion that the persons entrusted with the administration ought to be ready to give an account of the whole and of every part of it.
  You consider me in a wrong point of view when you speak of me as an accuser. As a freeman and the representative of free Men I considered it as both my right and duty to call upon the executive to account for our numberless miscarriages and losses so far as they were concerned in or might have prevented them. In doing this I had no private pique to gratify….
  At your request I will mention such things as strike me at present as want[ing] explanation and if any thing shall hereafter occur I will inform you by letter.
  The total want of opposition to Arnold on his first expedition to Richmond.
  The dissolution of a considerable body of militia on our Southern frontier at the time of Green’s retreat for want of orders from the executive.
  The want of timely orders to the counties of Amherst Augusta &c. after the adjournment of the Assembly from Richmond.
  The great loss that the country has sustained in arms &c. exclusive of those destroyed by the enemy.
  The rejection of an offer made by Cols. Campbell Christian and McDowell to raise regiments for the Southern Service.” [PTJ 7:105-106]

Jefferson responds to George Nicholas's call to account for his administration

Jefferson to George Nicholas, 28 July 1781:
“Sir,
"I am informed that a resolution on your motion passed the House of Delegates requiring me to render account of some part of my administration, without specifying the act to be accounted for. As I suppose that this was done under the impression of some particular instance or instances of ill conduct, and that it could not be intended first, to stab a reputation by a general suggestion under a bare expectation that facts might be afterwards hunted up to bolster it, I hope you will not think me improper in asking the favor of you to specify to me the unfortunate passages in my conduct which you mean to adduce against me, that I may be enabled to prepare to yield obedience to the House while facts are fresh in my memory and witnesses and documents are in existence.
I am Sir
Your most obedt. Servt."

Jefferson learns he is being investigated by the Virginia House of Delegates for misconduct

Archibald Cary

Archibald Cary to Jefferson, 19 June 1781: “You must have heard that Nelson is your successor [as Governor].” Russia and Austria have offered to mediate between the US and Britain.  “At length the Assembly are giving Ample Powers to the Executive. The Bill for that purpose stands for a Committee of the Senate this day and will Pass. It is what that body have long Wished. A Bill has Passed both Houses for establishing Martial Law 20 Miles round both Armys.”

“So Much for Assembly but I must give you one more peice of News respecting your Self. An Address was ready to be offered the Senate to you. What Can you think Stopt it? George Nicholas made a Motion in the Delegates House for an Inquire into your Conduct, a Catalogue of omissions, and other Misconduct. I have not Seen the Particulars. Your Friends Confident an Inquire would do you Honor Seconded the Motion. I presume you will be Serv’d with the order. As this Step was Taken I persuaided Winston not to make his Motion; I had heard something of this Kind was to be brought on the Carpit, and If I know you, it will Give you no pain.” PTJ 7:96-97  

Ex-Governor Jefferson under fire

For several days after regrouping in Staunton after Tarleton's attack on Charlottesville, the Virginia Assembly continued fruitlessly to issue resolutions to the governor, not realizing that he had relinquished the seat on June 1. On June 12, after electing his successor, the House also voted to conduct “an inquiry into the conduct of the Executive for the past twelve months” to account for the “numberless miscarriages and losses” Virginia had suffered during his administration. This was a particularly insensitive phrase to one whose wife had experienced miscarriages and who had recently lost their third child.

On June 19, Jefferson's friend Archibald Cary, the Speaker of the Senate, caught him up on events in the Virginia legislature. "You must have heard that Nelson is your successor," he reported. Moreover, the House had voted to give "Ample Powers to the Executive"--in other words, to empower a dictator--and the Senate was likely to concur. At last, Cary came to the real point:

So Much for Assembly but I must give you one more peice of News respecting your Self.,,,George Nicholas made a Motion in the Delegates House for an Inquire into your Conduct, a Catalogue of omissions, and other Misconduct. I have not Seen the Particulars. Your Friends Confident an Inquire would do you Honor Seconded the Motion. I presume you will be Serv’d with the order....I had heard something of this Kind was to be brought on the Carpit, and If I know you, it will Give you no pain.

Cary clearly did not know Jefferson. He was stricken by the news, utterly and permanently mortified.  For the rest of his life, he would recall the Assembly's action--which he attributed to the machinations of Patrick Henry--with bitterness and shame.