1) Best way to drive 2) How a watchdog responds 3) How sentries should patrol 4) In a completely awake way 5) In a heads-up manner 6) In a wary way 7) In a wide-awake manner 8) In an alert manner 9) In an attentive fashion 10) In nimble fashion 11) Vigilantly 12) With all ears 13) With attentiveness Found on https://www.crosswordclues.com/clue/alertly