Exhibit 24

                               POWER OF ATTORNEY

       KNOW ALL BY THESE PRESENTS, that the undersigned hereby makes,
constitutes and appoints Jeffery Schwartz, Andrew Hack and David Hutchins,
acting singly and with full power of substitution or revocation, the
undersigned's true and lawful attorney-in-fact, with full power and authority as
hereinafter described on behalf of and in the name, place and stead of the
undersigned to:

       (i)   execute for and on behalf of the undersigned, in the undersigned's
             capacity as a director, director nominee, officer or beneficial
             owner of ordinary shares of BCLS Acquisition Corp., a Cayman
             Islands exempted company (the "Company"), any Schedule 13D or
             Schedule 13G, and any amendments, supplements or exhibits thereto
             (including any joint filing agreements) required to be filed by the
             undersigned under Section 13 of the Securities Exchange Act of
             1934, as amended, and the rules promulgated thereunder (the
             "Exchange Act"), and any Forms 3, 4, and 5 and any amendments,
             supplements or exhibits thereto required to be filed by the
             undersigned under Section 16(a) of the Exchange Act;

      (ii)   do and perform any and all acts for and on behalf of the
             undersigned which may be necessary or desirable to complete and
             execute any such schedules or forms and timely file such forms with
             the United States Securities and Exchange Commission and any
             applicable stock exchange; and

     (iii)   take any other action of any type whatsoever in connection with the
             foregoing which, in the opinion of such attorneys-in-fact, may be
             of benefit to, in the best interest of, or legally required by, the
             undersigned, it being understood that the documents executed by
             such attorneys-in-fact on behalf of the undersigned pursuant to
             this Power of Attorney shall be in such form and shall contain such
             terms and conditions as such attorneys-in-fact may approve in such
             attorneys-in- fact's discretion.

             The undersigned hereby grants to such attorneys-in-fact full power
and authority to do and perform any and every act and thing whatsoever
requisite, necessary, or proper to be done in the exercise of any of the rights
and powers herein granted, as fully to all intents and purposes as the
undersigned might or could do if personally present, with full power of
substitution or revocation, hereby ratifying and confirming all that such
attorneys-in-fact's substitute or substitutes, shall lawfully do or cause to be
done by virtue of this power of attorney and the rights and powers herein
granted. The undersigned acknowledges that the foregoing attorneys-in-fact, in
serving in such capacity at the request of the undersigned, are not assuming,
nor is the Company assuming, any of the undersigned's responsibilities to comply
with, or any liability for the failure to comply with, Section 13 and/or Section
16 of the Exchange Act.

       This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file reports or schedules under Section 13
or Section 16 of the Exchange Act with respect to the Company, unless earlier
revoked by the undersigned in a signed writing delivered to the foregoing
attorneys-in-fact.

                                 *  *  *  *  *



       IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to
be executed as of this 21st day of October, 2020.

                                By: /s/ Adam Koppel
                                    ---------------------------------
                                Name:  Adam Koppel
                                Title: Chairman