UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

(Amendment No. 1)

FORM 10-Q/A

(MARK ONE)

x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarter ended September 30, 2025

¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission file number: 001-42252

TERRESTRIAL ENERGY INC.

(Exact Name of Registrant as Specified in Its Charter)

Delaware		98-1785406
(State or other jurisdiction of incorporation or organization)		(I.R.S. Employer Identification No.)

2730 W. Tyvola Road, Suite 100

Charlotte, NC

28217

(Address of principal executive offices)

(Zip Code)

(646) 687-8212

(Issuer’s telephone number)

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, par value $0.0001 per share	IMSR	The Nasdaq Stock Market LLC
Redeemable Warrants, each whole warrant exercisable for one Common Stock at a price of $11.50 per share	IMSRW	The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x No ¨

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes x No ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer	¨	Accelerated filer	¨
Non-accelerated filer	x	Smaller reporting company	x
		Emerging growth company	x

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ¨ No x

As of November 14, 2025, there were 81,771,423 shares of the registrant’s common stock, $0.0001 par value, outstanding. In addition, as of November 14, 2025, there were 24,011,029 shares of the registrant’s common stock issuable upon exchange of outstanding exchangeable shares of a subsidiary, which are convertible into shares of common stock of the registrant on a one for one basis.

EXPLANATORY NOTE

This Amendment No. 1 on Form 10-Q/A (the “Amendment”) is being filed solely (i) to correct the number of shares of common stock outstanding on the cover page of the registrant’s Form 10-Q for the period ended September 30, 2025 (the “Original Filing”) filed with the Securities and Exchange Commission (the “Commission”) on November 14, 2025 and (ii) to correct the cover page check boxes erroneously indicating that the registrant was a shell company as of Original Filing and had not filed all reports required to be filed during the preceding 12 months. As previously reported in the Form 8-K filed by the registrant on November 3, 2025, the registrant ceased being a shell company upon the completion of the Merger as described in such Form 8-K. No other changes have been made to the Original Filing, whether to update the Original Filing to reflect events occurring subsequent to the filing of the Original Filing or otherwise.

As required by Rule 12b-15 of the Securities Exchange Act of 1934, as amended, this Form 10-Q/A contains new certifications by the registrant’s principal executive officer and principal financial officer under Section 302 of the Sarbanes-Oxley Act of 2002, which are being filed as exhibits to this Form 10-Q/A. Because this Form 10-Q/A includes no financial statements, the registrant is not including certifications pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

Item 6. Exhibits

The following exhibits are filed as part of, or incorporated by reference into, this Quarterly Report on Form 10-Q.

No.		Description of Exhibit
31.1*		Certification of Principal Executive Officer Pursuant to Securities Exchange Act Rules 13a-14(a), as adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
31.2*		Certification of Principal Financial Officer Pursuant to Securities Exchange Act Rules 13a-14(a), as adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
101.INS		Inline XBRL Instance Document
101.SCH		Inline XBRL Taxonomy Extension Schema Document.
101.CAL		Inline XBRL Taxonomy Extension Calculation Linkbase Document.
101.DEF		Inline XBRL Taxonomy Extension Definition Linkbase Document.
101.LAB		Inline XBRL Taxonomy Extension Label Linkbase Document.
101.PRE		Inline XBRL Taxonomy Extension Presentation Linkbase Document.
104		Cover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101).

*	Filed herewith

PART III - SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this Amendment No. 1 to be signed on its behalf by the undersigned, thereunto duly authorized.

	TERRESTRIAL ENERGY INC. f/k/a HCM II ACQUISITION CORP.

Date: November 20, 2025	By:	/s/ Simon Irish
		Simon Irish
		Chief Executive Officer
		(Principal Executive Officer)

Date: November 20, 2025	By:	/s/ Brian Thrasher
		Brian Thrasher
		Chief Financial Officer
		(Principal Financial Officer)

Amendment: SEC Form 10-Q/A filed by Terrestrial Energy Inc.