The Iron Hand of Mars is a 1992 historical mystery crime novel by Lindsey Davis and the fourth book of the Marcus Didius Falco Mysteries series. Set in Rome and Germania during AD 71, the novel stars Marcus Didius Falco, informer and imperial agent. The iron in the title refers to the standard, shaped like a giant hand made of iron, which Falco is required to deliver to the imperial legions in Germany.
Plot summary
Following the events of Venus in Copper, the Imperial authorities are seeking Falco out for an assignment in Germany (which given the events of his last mission abroad, Falco is slow to accept). Meanwhile, Falco is not pleased with Titus Caesar attempting to seduce Helena. When Helena gets an invitation to a private dinner with Titus, she pleads that Falco stay by her side on the same day, but he instead decides to see a client in Veii — who unfortunately turns out to be a widow more intent on pleasure than business. Disgusted, Falco returns to Rome, but Helena has disappeared, apparently leaving Falco for good. Romantically depressed, Falco goes over to the Palatine to be personally briefed by the emperor Vespasian on his latest assignment — broker peace between Rome and the Celtic tribes of Germany (whose leaders are thought to be Veleda, a priestess and Julius Civilis, a local strongman), locate a missing military officer named Munius Lupercus, and deliver a new standard in the form of a two-foot long human hand, cast in iron, to the 14th Gemina at Moguntiacum — the last actually being a pretext for Falco to investigate them, given that the 14th's loyalty is held in doubt. Much to Falco's annoyance, he is also to escort an ex-slave named Xanthus into Germany as well, whose specialty is hairdressing.
Falco's trip is marked by a number of misadventures — poor food and even poorer wine, unscrupulous souvenir sellers and cramped conditions, as well as murder. At Lugdunum, Falco and Xanthus bump into two travellers quarrelling with a group of potters, who are later found murdered. At the crime scene, Falco makes the acquaintance of a centurion named Helvetius, before trying to contact Helena's brother Justinus, a military tribune serving at Argentoratum, but discovers that Justinus has been transferred elsewhere, and so proceeds down the Rhenus further into Germany, where the relatively wealthy Xanthus is accosted by a peddler named Dubnus. Falco discovers that Dubnus is selling curios which may have been relics of Varus' ill-fated expedition, and asks Dubnus about Veleda, who tells him that she lives in a tower in the middle of the forest somewhere in the north.
At Moguntiacum, Falco tries to contact the local military legate, Florius Gracilis, but discovers that like Lupercus, Gracilis is missing. Falco finally meets Justinus and upon discussing Gracilis further, he discovers that Gracilis has been absent without leave, and his whereabouts are unknown, and in addition to his official duties, begins tracking down Gracilis. Running out of leads, Falco finally tries to make enquiries with the camp prefect of the 14th Legion, but accidentally lets it slip that he was part of the infamous 2nd Augusta. Brusquely driven off and humiliated, he is warned by to cease his inquiries. Later, three apparently drunk soldiers attack Falco, but he is saved by Xanthus who kills one of the soldiers, and finally discovers that Justinus has another guest, and it's none other than Helena, who has also brought along his niece, Augustinilla, because her mother, Victorina, is having "woman problems".
Falco and Helena go shopping and meet a German potter, Julius Mordanticus, whose uncle Bruccius has gone missing along with his cousin in Gaul. Falco immediately identifies Mordanticus' relatives as the men killed in Gaul, and tells Mordanticus to contact Helvetius, while Helena uncovers strong business rivalry between the potters of Lugdunum and Moguntiacum over commercial contracts to supply high-quality ceramics to the Roman army — suggesting that Gracilis himself was bribed by Lugdunum. Helena then buys a bowl from Julius Mordanticus for Falco to bring back as a gift for his mother in Rome.