Exhibit 10.4

SECOND AMENDMENT TO PURCHASE AGREEMENT

THIS SECOND AMENDMENT TO PURCHASE AGREEMENT (this “ Amendment ”) is made as of August 6, 2009 by and between HUB PROPERTIES TRUST , a Maryland real estate investment trust (the “ Seller ”), and SENIOR HOUSING PROPERTIES TRUST , a Maryland real estate investment trust (the “ Purchaser ”).

W I T N E S S E T H

WHEREAS , the Seller and the Purchaser executed a Purchase and Sale Agreement dated as of May 5, 2008, as amended by that certain First Amendment to Purchase Agreement, dated December 23, 2008 (as amended, the “ Purchase Agreement ”), with respect to the Property (this and other capitalized terms used and not otherwise defined herein shall have the meanings given such terms in the Purchase Agreement) described in Exhibit A hereto; and

WHEREAS , the Seller and the Purchaser now wish to amend the Purchase Agreement subject to and upon the terms and conditions set forth herein;

NOW, THEREFORE , for good and valuable consideration and in consideration of the mutual covenants of the parties hereto, the mutual receipt and legal sufficiency of which is hereby acknowledged, Landlord and Tenant hereby agree as follows:

1.             Section 2.2 is hereby deleted in its entirety and the following is inserted in substitution therefor:

2.2            Closing .   The purchase and sale of the Property shall be consummated at a closing (the “ Closing ”) to be held at the offices of Sullivan & Worcester LLP, One Post Office Square, Boston, Massachusetts, or at such other location as the Seller and the Purchaser may agree, at 10:00 a.m., local time, on August 6, 2009 (the “ Closing Date ” ).

2.