The resistance discusses plans for the future in episode 1x04 “Coming Back”. Sheema brings the plans for the tunnels to the resistance in episode 1x05 “Fear Her”. Sheema is interrogated after the failed mission in episode 1x06 “Nothing Matters”.
Tunnel under Julius's Lair
Vanessa and Axel climb out of the tunnel after leaving the hospital in episode 1x03 “Stay Inside”.
The resistance is ambushed while attempting to sneak into the vampire lair in episode 1x06 “Nothing Matters”.
From episode #105 "Fear Her".