Passage 8.50.10
μετὰ δὲ ταῦτα Νάβις μὲν ἐς εἰρημένον χρόνον σπονδὰς παρὰ Ῥωμαίων εὑράμενος τελευτᾷ, πρὶν ἤ οἱ τοῦ πολέμου τὰς ἀνοχὰς ἐξήκειν, ὑπὸ ἀνδρὸς Καλυδωνίου κατὰ δὴ συμμαχίας πρόφασιν ἥκοντος, πολεμίου δὲ τῷ ἔργῳ καὶ ἐπʼ αὐτὸ ἐσταλμένου τοῦτο ὑπὸ τῶν Αἰτωλῶν.
After these events, Nabis, who had obtained a truce from the Romans for a specified period, met his end before the agreed cessation of hostilities had expired. He was killed by a man from Calydon, who had arrived ostensibly as an ally, but who, in practice, was hostile and had been sent specifically for this purpose by the Aetolians.