Passage 7.15.3
τότε δὲ ὡς παρὰ τῶν κατασκόπων ἐπυνθάνετο ὁ Κριτόλαος Μέτελλον καὶ Ῥωμαίους διαβεβηκέναι τὸν Σπερχειόν, ἀπέφευγεν ἐς Σκάρφειαν τὴν Λοκρῶν, οὐδὲ κατὰ τὸ στενὸν τὸ Ἡρακλείας τε μεταξὺ καὶ Θερμοπυλῶν τοὺς Ἀχαιοὺς τάξας ἐτόλμησεν ὑπομεῖναι Μέτελλον· ἀλλὰ ἐς τοσοῦτο ἀφίκετο δείματος ὡς μηδὲ αὐτὸ ποιήσασθαι τὸ χωρίον πρὸς ἀμείνονος ἐλπίδος, ἔνθα ἦν μὲν Λακεδαιμονίοις ὑπὲρ τῶν Ἑλλήνων τὰ ἐς Μήδους, ἦν δὲ καὶ Ἀθηναίοις τὰ ἐς Γαλάτας οὐδὲν ἀφανέστερα ἐκείνων τολμήματα.
Then, when Critolaus learned from his spies that Metellus and the Romans had crossed the Spercheius, he retreated to Scarpheia in Locris; nor did he venture to arrange the Achaeans and await Metellus at the narrow pass lying between Heraclea and Thermopylae. Indeed, such fear overtook him that he did not even attempt to make a stand at a site where there might have been a better hope, the very place where the Spartans had fought for Greece against the Persians, and where the Athenians had performed deeds no less remarkable against the Gauls.