Power of Attorney for Patricia A. Norton-Gatto

This filing details a Power of Attorney granted by Patricia A. Norton-Gatto, an SVP & Principal Accounting Officer of The Hanover Insurance Group, Inc., to various individuals, including Lindsay L. Katz. The power of attorney authorizes the appointed individuals to act on Ms. Norton-Gatto's behalf regarding SEC filings (Forms 3, 4, and 5) using the EDGAR system. This includes executing and filing these forms, managing EDGAR account access, and obtaining information about transactions in the company's equity securities. The document also clarifies that while the appointed attorneys-in-fact are authorized to act, Ms. Norton-Gatto remains responsible for compliance with Section 13 or Section 16 of the Exchange Act. The power of attorney is effective until Ms. Norton-Gatto is no longer required to file such forms or until revoked in writing. The filing also includes details of stock options granted to Ms. Norton-Gatto with specific vesting schedules and exercise prices, as well as restricted stock units.