I will assume that he is leaving for higher salary,and therefore I will offer him higher salary than the competing firm,and make sure that he stays.
I will try to understand why is he quitting,and will start negotiation process to retain him.
I will make sure that we have a back up,and find somebody who can replace him quickly and effectively.
I will use all available option including coercion and will enforce him to stay until I find his replacement.
I will beg him to stay and will make an emotional speech,and remind him of earlier days asking him to stay.
I will make sure that I allocate him more work ,so that he just can not study during his office time.
I will call him in my office and will explain him some of the local MBA programs that the organization reimburses for top performing resources.
I will remove him from all critical projects,and ensure that he is not part of any long term projects.
I will approach him,and talk with him to understand what books and courses he is using for his MBA preparations.
I will report his extra-curricular exam preparation activities to my boss informally,this will ensure I am safe in case he quits or there is some impact on his projects.
I will quickly call home,explain the situation to my wife,talk to my son-explain the situation,hoping that they will understand and quickly start working on the presentation.
I will ask my competitive team mate to present it on my behalf,knowing that he will reap all the benefits and take the entire credit.
I will talk with my dynamic CEO,explain him the situation and will ask him to reschedule the meeting with Japanese.
I will talk directly with my Japanese counterpart,explain them the situation and request them to delay or reschedule the meeting.
I will try to quickly wrap-up the meeting, finish the job,and rush home even though I know that birthday party is over by now.