As before, I haven't explained the plot much here because I've already gone through it in detail in my posts on the TV adaptation.
I think the most interesing thing about this adaptation of I, Claudius and Claudius the God is the pacing. With only six episodes, it's inevitable that much of the two source novels will be a bit rushed, but the amount of space given to each emperor is surprising to me - halfway into episode 2, Augustus is already dead. Considering the length of Augustus' reign compared to those of the other three emperors featured (Tiberius, Caligula and Claudius - Tiberius and Claudius had decent enough innings but Caligula's reign was very short) it's surprising to lose him before the end of episode 2. I think this is mainly due, as I disussed last week, to the radio series wanting to focus a bit more on the figure of Claudius himself, who was born later in Augustus' reign, but having said that, much of the second half of the episode focussed on Tiberius, Germanicus and Caligula, not Claudius.
Augustus' death itself is announced rather abruptly by messengers to Claudius, which gives it a brutal feeling that would otherwise be hard to get across on radio, but does rather deny listeners a proper goodbye to Augustus, who is last heard insisting that he'll drink only water from the well and eat only figs from the tree. The specifics of how Livia poisoned the figs have not yet been revealed and will presumably be detailed in a later episode.
Tiberius, meanwhile, maintains at this point a surprisingly good relationship with his mother, though after Augustus' death we hear Sejanus start to plant seeds of rebellion in him. He's a bit slow to catch on to some things, not noticing that Augustus headed off towards Planasia, where Postumus was banished, until it is pointed out to him - though his question to Livia concerning whether her hired bandits she set on Augustus' friend were expensive is quite amusing. In general, Tiberius comes over rather weakly in his own episode, moves around as a pawn by Livia and Sejanus and bumbling a bit. He only really sounds authoritative in his scene with Claudius (which revolves around getting Claudius to look respectable but not actually giving him anything to do), because Claudius is nervous and uncomfortable in his presence. To everyone else, however, he is more or less a tool of his mother and Sejanus, who are fighting over him and through him (though without any scenes together - everything is done using Tiberius himself as a conduit).
While some aspects of the novels are whizzed through at speed, others get a fair bit of attention here, certainly more than in the much longer television version (all stemming from the novels, of course, which have no time constraints). Most interestingly, we are given a much fuller introduction to Cassius Chaerea, the man who led the plot to assassinate Caligula. Graves introduces Chaerea in the amphitheatre, fighting Germans, puts him in the Battle of Teutoberg Forest as one of the few survivors and then (more correctly) puts him in Germanicus' army, where he has Cassius as the soldier who leads Caligula and Aggripina away from the mutiny, encouraging the soldiers to back down. The radio adaptation includes all of these, so that we are quite familiar with Cassius and with his relationship with Caligula, well in advance of Caligula's reign and assassinationn (in marked contrast to the TV series, which suddenly introduces Cassius in the episode in which Caligula is killed and leaves us all wondering what happened to Gimli). All this preparation will pay off when we reach the assassination of Caligula, but at the moment the amount of attention paid to Cassius, and his remarkable ability to be involved in every major event going, is surprising - though, given the difficulty of telling characters apart on radio, probably a good idea, as it gives listeners a character and voice to recognise in these various situations.
It seems that we will be going into the death of Germanicus in much more detail than previous deaths and downfallsin this series (though Postumus got a bit of air-time). This episode lays the groundwork, in terms of his death itself and the motivations behind his murder. The actual murder is very effectively done, with the voice of a not-yet-identified Caligula whispering the letters of Germanicus' name as he writes them on the wall, one letter shorter each day, terrifying his father into fatal ill health (combined with poison). It seems that this will be what finally drives Tiberius and Livia apart as well, as they are still reasonably close at this point, Tiberius conspiring with her, though he is already using his own spies and paid informers, since she won't let him use hers. All this will be for the next episode, however, as this one ends with the death of Germanicus. It's an interesting choice - personally, I think I prefer the TV's method of putting Germanicus' death and Piso and Plancina's trial for his murder into one episode, and I would have given Augustus a bit more time, but it does act as quite an effective cliffhanger of sorts for episode 3.
There are some fun touches in the language; calling 'French' warriors 'Frogs' is doubly inaccurate (modern France was inhabited by Gauls at the time, and no one called them 'Frogs') but it is funny and gets a sense of reality across to a modern audience by making the dialogue sound more familiar. Cassius Chaerea's accent is a bit rougher around the edges than I'd expect, presumably to mark him out as a soldier and practical man, though in reality I suspect he was reasonably well off and wouldn't have had an overly strong accent (on the other hand, we don't really know what Roman accents were like, so it doesn't really matter!).
The best thing about this episode is the groundwork it lays for future developments - Sejanus is introduced and his methods become clear, Rome becomes dangerous enough that Herod leaves and advises Claudius to hide (which forms a nice structural circle with the episode's opening scene, which is Pollio's advice to Claudius to exaggerate his limp and stammer and appear foolish. He does this a bit too well around his mother, who dislikes him more than ever). Caligula is given a very thorough introduction and Cassius is introduced as well, so we will know lots about them by the time they reach breaking point. I'm not sure how some of this comes across to anyone who doesn't already know the story, but the scenes in the amphitheatre, and of the mutiny of Germanicus' troops, and of Germanicus' murder are exciting and effective so I doubt that's a problem. And, of course, the best thing about radio is that we can experience mutinies and Games and journeys across Germania with our characters, because there is no budgetry problem in depicting any of these things, allowing the adaptators to make choices based much more on what they think is most important and less on what they can afford.