Exhibit 24

                               POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below
hereby constitutes and appoints Mark McDonnell his true and lawful attorney-in-
fact, with full power of substitution, to sign any and all instruments,
certificates and documents that may be necessary, desirable or appropriate to be
executed on behalf of himself as an individual or in his capacity as a direct or
indirect general partner, director, officer or manager of any partnership,
corporation or limited liability company, pursuant to section 13 or 16 of the
Securities Exchange Act of 1934, as amended (the "Exchange Act"), and any and
all regulations promulgated thereunder, and to file the same, with all exhibits
thereto, and any other documents in connection therewith, with the Securities
and Exchange Commission, and with any other entity when and if such is mandated
by the Exchange Act or by the Financial Industry Regulatory Authority, granting
unto said attorney-in-fact full power and authority to do and perform each and
every act and thing necessary, desirable or appropriate, fully to all intents
and purposes as he might or could do in person, thereby ratifying and confirming
all that said attorney-in-fact, or his substitutes, may lawfully do or cause to
be done by virtue hereof.

        IN WITNESS WHEREOF, this Power of Attorney has been signed as of the
29th day of January, 2021.

                        ARCH VENTURE FUND X, L.P.

                        By:     ARCH Venture Partners X, L.P.
                                its General Partner

                                By:    ARCH Venture Partners X, LLC.
                                       its General Partner

                                       By:     /s/ Keith Crandell
                                           ------------------------------
                                           Managing Director

                       ARCH VENTURE PARTNERS X, L.P.

                       By:     ARCH Venture Partners X, LLC
                               its General Partner

                               By:     /s/ Keith Crandell
                                   ----------------------
                                   Managing Director

                        ARCH VENTURE PARTNERS X, LLC

                        By: /s/ Keith Crandell
                            ------------------
                            Managing Director

                        /s/ Keith Crandell
                        ------------------------
                        Keith Crandell

                        /s/Robert Nelsen
                        ------------------------
                        Robert Nelsen

                        /s/Kristina Burow
                        -----------------
                        Kristina Burow

                        /s/Steven Gillis
                        -----------------
                        Steven Gillis