In Saturnalia, Falco has to track down an important prisoner that no-one must know has escaped from custody. His rival Anacrites kidnaps Falco's brother-in-law to use as bait, since they are the only two people who really know what the fugitive looks like. Anacrites holds Justinus at his mansion, and after visiting him, his family are content to send him reading matter and let him wait it out there. Then, Falco, whilst attending the vigiles' Saturnalia party (which includes two guests dressed as a carrot and a turnip), hears that some of the fugitive's countrymen also know of the connection between Justinius and the fugitive, and decide to kidnap him again. So Falco and Petro go to Anacrites' mansion first with a handful of vigiles, set fire to some garden waste, and force their way in under the pretext of their official duty as firefighters. The entire place ends up on fire, with many valuable ornaments removed permanently by the vigiles, Justinus is rescued, and Anacrites' major domo has the situation explained to him by a vigile dressed as a carrot, who Anacrites orders the arrest of as soon as he hears. Naturally the vigiles have no idea who he's talking about, so Anacrites heads to the vigiles' party with a squad to search for Falco and Justinius. The vigiles swear Falco and Petro haven't left all evening, and Anacrites leaves when a man dressed as a turnip keeps drunkenly barging into him. Falco and Petro then take the turnip back to Falco's old apartment, where it's revealed that it's Justinius now in the turnip costume.
The scene in Last Act In Palmyra where the players bump into some Christians, get preached to and end up beating them up and running for their lives (and souls) made this troper laugh.
Or the introduction of each chapter, which is written in the form of a play.
In the first book, Falco and Helena are on the run. Falco tells her 'Stay here and try to look like an amphora.' Helena then does her best to imitate a wine jug.
Shadows in Bronze. The amorous adventures of Nero the ox. That eventually gets Falco arrested for blasphemy (for giving the ox an Emperor's name, for the record).
"We called Nero "Spot" and were ignored. We tried calling Nero "Nero" and he ignored that too."
I even spotted in rather shy, small letters on a temple column an impassioned mutter of:
Aelia Annaea has three brothers. All of them have long names starting with 'Lucius Annaeus'. She, however, refers to them as 'Spunky, Dotty and Ferret', and the narration dutifully calls them that.
From the same book:
Falco: He's an idiot! I should have found out earlier-
Helena: How could you? He never would have just admitted, Yes, Your Honour, I'm an idiot.
Falco and Helena formulate a phrasebook for Albia which has many useful phrases in other languages. These range from the icebreaker 'Do you suffer many earthquakes here?' to such gems as 'Please excuse my husband farting at the dinner table, he has a dispensation from the Emperor Claudius' (which is actually true).
The marriage of Smaractus and Lenia. He gets so hammered that he can barely stand and she throws a massive shit fit when he shows up drunk. All the guests get equally hammered, and while the two of them are consummating, the bed and floor catch fire (though nobody gets hurt). Smaractus, when he's rescued, gets arrested for arson, and all the wedding presents are stolen. They spend about five books screaming at each other over their divorce proceedings.