insidiously
From LSJ
Ἕκτορ νῦν σὺ μὲν ὧδε θέεις ἀκίχητα διώκων → Hector, you run in pursuit of something unattainable | Hector, now art thou hasting thus vainly after what thou mayest not attain | Hector, now you are hasting thus vainly after what you may not attain
