This is by far not the first episode where Jack and Mason sort of reunite again i. e. stop working against each other, but this episode cements this new agreement, and it does so in a complex and therefore interesting way. Mason is drawn as a rather cold and authoritative, also controlling superior, but may it be the writers intention, may it be Xander Berkeley as an actor or a nice merger of these two factors: Mason is also an entertaining element in the series and can be quite a nice guy too, seeing his limits and cunningly arranging things around his limitations instead of giving other people a hard time because of them... what I'm trying to say is: Mason realizes that he himself will never have the ability to solve this case, so he simply follows Jack and also lets him do his job. And Jack, appreciating that he's not hindered to do what he thinks best, readily involves his superior who therefore can stay on top of what's happening. Both help each other out. Jack doesn't think hierarchically, so he doest't mind Mason getting nowhere without him and kind of using him as long as he can work. Also this means Mason accepts Jacks work. The pair is having a nice conversation demonstrating all that in the car on their way to the power station.
Mason deceives Jack by not telling him about his family in this episode. So it becomes clear: the two won't become friends. But even this betrayal doesn't affect their new good companionship.
The only question remains whether it is really convincing that Mason forgets about their initial fight. Somehow it's unbelievable this character should change so much. And also I always kept wondering what kind of information Mason originally kept hidden from Jack - because after Jack has the information, just as much is happening as when he didn't have it: nothing.
Mason deceives Jack by not telling him about his family in this episode. So it becomes clear: the two won't become friends. But even this betrayal doesn't affect their new good companionship.
The only question remains whether it is really convincing that Mason forgets about their initial fight. Somehow it's unbelievable this character should change so much. And also I always kept wondering what kind of information Mason originally kept hidden from Jack - because after Jack has the information, just as much is happening as when he didn't have it: nothing.