Shawn Levy's third and allegedly final Night at the Museum film is subtitled Secret of the Tomb even though we only briefly see a tomb. This is probably because Goes to London isn't nearly as marketable, and Robin Williams' Final Live-Action Performance would be too morbid. A sense of melancholy does hang over the shockingly not-terrible film, likely built into the script before anyone knew it would be Williams' last movie. Storywise, night watchman Larry (Ben Stiller) travels to the British Museum with Teddy Roosevelt (Williams) and other historical exhibits to fix the magical doodad that grants them life, lest they all remain inanimate forever. Along for the ride is Larry's boring son Nick (Skyler Gisondo) for a boring subplot about Larry not being able to let Nick become his own man, yawn. That stultifying plotline notwithstanding, Secret of the Tomb has all the CGI shenanigans one expects from this series — including a genuinely clever trip inside M. C. Escher's Relativity — and a running gay-panic joke which is not okay, but it's most effective in its quieter moments. Unsurprisingly, some of the funniest lines are clearly improvisations, and Williams gets in a few good ones. It ain't The Fisher King, but considering how his career went, he could have had a much worse sign-off.