Material Agreement (Form 8-K)

Item 1.01 Entry into a Material Definitive Agreement.

Amendment to Sponsor Support Agreement

On September 5, 2025, Plum Acquisition Corp. III, a Cayman Islands exempted company ("Plum"), Tactical Resources Corp., a corporation formed under the Laws of the Province of British Columbia ("Tactical"), Plum III Merger Corp. ("Pubco"), Mercury Capital, LLC (the "Sponsor") Alpha Partners Technology Merger Sponsor LLC (the "Former Sponsor") and certain shareholders of Plum entered into an amendment (the "Sponsor Support Agreement Amendment") to the Sponsor Support Agreement, dated as of August 22, 2024 (as amended, the "Sponsor Support Agreement"). Capitalized terms used but not defined herein have the meanings ascribed to such terms in the Sponsor Support Agreement.

The Sponsor Support Agreement Amendment provides that, immediately prior to the closing (the "Closing") of the previously announced business combination among Plum, Tactical and Pubco (the "Business Combination"), to the extent that any Sponsor Incentive Units (as defined in the Sponsor Support Agreement) have not been transferred by the Sponsor to PIPE Investors, SPAC Public Shareholders or other third parties as provided for in the Sponsor Support Agreement, such remaining Sponsor Incentive Units will be retained by the Sponsor subject to vesting based on the achievement of certain trading prices of the Pubco Common Shares after the Closing, as described in more detail in the Sponsor Support Agreement Amendment. In the event that such trading prices have not been achieved on or before the tenth anniversary of the Closing, such Sponsor Incentive Units shall be surrendered to Pubco for cancellation for no consideration and shall cease to represent any interest in Pubco, effective as of such date.

Amendment to Purchase Agreement

On September 5, 2025, the Sponsor, Plum and the Former Sponsor entered into an amendment (the "Purchase Agreement Amendment") to the Purchase Agreement, dated December 27, 2023 (as amended, the "Purchase Agreement"). The Purchase Agreement Amendment provides that, to the extent that any Sponsor Incentive Units have been retained by the Sponsor after the Closing, up to half of such Sponsor Incentive Units may be transferred prior to the Closing to a third party, with any Sponsor Incentive Units remaining after such transfer subject to allocation between the Sponsor and the Former Sponsor as provided for in the Purchase Agreement.

Copies of the Sponsor Support Agreement Amendment and the Purchase Agreement Amendment are filed with this Current Report on Form 8-K as Exhibits 10.1 and 10.2, respectively. Each are incorporated herein by reference, and each of the foregoing descriptions of the Sponsor Support Agreement Amendment and the Purchase Agreement Amendment is qualified in its entirety by reference thereto.

Additional Information and Where to Find It

In connection with the Business Combination, the parties have prepared, and Pubco has filed with the SEC, a registration statement on Form F-4 and amendments thereto (the "Registration Statement"). The Registration Statement contains a preliminary proxy statement/prospectus of Pubco, and after the Registration Statement is declared effective, Plum will mail the Registration Statement containing a definitive proxy statement/prospectus relating to the Business Combination to its shareholders and Tactical will prepare and mail an information circular relating to the Business Combination to its shareholders. This Current Report does not contain all of the information that should be considered concerning the Business Combination and is not a substitute for any proxy statement, registration statement, proxy statement/prospectus, information circular or other documents Plum, Pubco or Tactical may file with the SEC or the Canadian Securities Administrators (the "CSA") from time to time in connection with the Business Combination. INVESTORS AND SECURITY HOLDERS IN TACTICAL AND PLUM AND ALL OTHER INTERESTED PARTIES ARE URGED TO READ CAREFULLY AND IN THEIR ENTIRETY THE REGISTRATION STATEMENT WHEN IT BECOMES AVAILABLE, ANY AMENDMENTS OR SUPPLEMENTS TO THE REGISTRATION STATEMENT, AND OTHER DOCUMENTS FILED BY TACTICAL, PUBCO OR PLUM WITH THE SEC OR THE CSA IN CONNECTION WITH THE BUSINESS COMBINATION BECAUSE THESE DOCUMENTS WILL CONTAIN IMPORTANT INFORMATION. Investors and security holders in Tactical and Plum and all other interested parties will be able to obtain free copies of the Registration Statement and other documents filed by Tactical, Pubco or Plum with the SEC through the website maintained by the SEC at www.sec.gov and with the CSA through SEDAR+ at www.sedarplus.ca.