Exhibit 24

                                POWER OF ATTORNEY

Know all by these presents that Stephen D. Plavin, does hereby make, constitute
and appoint each of Geoffrey G. Jervis and Randall S. Rothschild or any one of
them, as a true and lawful attorney-in-fact of the undersigned with full powers
of substitution and revocation, for and in the name, place and stead of the
undersigned (in the undersigned's individual capacity), to execute and deliver
such forms that the undersigned may be required to file with the U.S. Securities
and Exchange Commission as a result of the undersigned's ownership of or
transactions in securities of Blackstone Mortgage Trust, Inc. pursuant to
Section 16(a) of the Securities Exchange Act of 1934, as amended, including
without limitation, statements on Form 3, Form 4 and Form 5 (including any
amendments thereto). The Power of Attorney shall remain in full force and effect
until the undersigned is no longer required to file Forms 3, 4, and 5 with
regard to his ownership of or transactions in securities of Blackstone Mortgage
Trust, Inc., unless earlier revoked in writing. The undersigned acknowledges
that Geoffrey G. Jervis and Randall S. Rothschild are not assuming any of the
undersigned's responsibilities to comply with Section 16 of the Securities
Exchange Act of 1934.

                                        By:    /s/ Stephen D. Plavin
                                               ---------------------------------
                                               Stephen D. Plavin

                                        Date:  May 30, 2013