Clarke, Finn, and Wells collect some plants for Jasper's wounds in a river in episode #103 "Earth Kills".
Lincoln works to heal Octavia's arrow wound on the shores of a river in episode #201 "The 48".
Clarke washes ashore and is saved by Anya after jumping off the dam in episode #203 "Reapercussions".
Clarke fakes passing out and then attacks Roan while he is transporting her in episode #302 "Wanheda, Part 2".
Octavia is watching a group take water samples for Pike when a Grounder kid approaches in episode #306 "Bitter Harvest".
Octavia falls down a hill while running from a mysterious pursuer in episode #105 "Twilight's Last Gleaming".
Lexa leads a procession with Finn's body to the Grounder town of Tondc in episode #209 "Remember Me".
Emori joins Murphy and they attempt another ambush only for Murphy to be taken captive in episode #305 "Hakeldama".
Clarke and Bellamy locate a supply bunker and find a bunch of guns in episode #108 "Day Trip".
The group investigates the crash site of the hijacked dropship in episode #110 "I Am Become Death".
The survivors from the ark set up camp in the remains of Alpha Station in episode #201 "The 48". The camp is renamed Arkadia and expanded in episode #301 "Wanheda".
Abigail goes to meet with Indra to try and negotiate a lighter sentence for Finn in episode #208 "Spacewalker".
Octavia leads people in a rescue attempt after the missile attack in episode #213 "Resurrection".
Clarke and Lexa hold their final war meeting before the assault near the base of Mount Weather in episode #215 "Blood Must Have Blood, Part 1".
Lincoln leads Clarke and Finn through the mines back to their camp in episode #112 "We Are Grounders, Part 1". Clarke and Anya have to escape through these tunnels in episode #203 "Reapercussions". Octavia and Indra lead and assault through the tunnels in episode #215 "Blood Must Have Blood, Part 1".
The group searching for the missing kids comes upon an ark crash site and rescues a girl stranded on a cliff face in episode #204 "Many Happy Returns".
Bellamy talks to Octavia outside the entrance to Mount Weather and two guards arrive with Echo in episode #303 "Ye Who Enter Here".
A girl from Mount Weather wakes up in a meadow outside the facility and quickly succumbs to the radiation in episode #207 "Long Into an Abyss". Later Carl Emerson arrives back at Mount Weather in episode #212 "Rubicon".
Clarke and Lexa prepare for the upcoming war with Mount Weather in episode #214 "Bodyguard of Lies".
Clarke, Lexa, and Lincoln locate the sniper from Mount Weather who is firing on Tondc in episode #213 "Resurrection".
Clarke and Lexa are riding back to Arkadia when they come upon the murdered Grounder army in episode #305 "Hakeldama".
Octavia rides to the Grounder village to warn them of the coming attack in episode #306 "Bitter Harvest"
Bellamy finds out his stolen key card has been deactivated and is set upon by guards in episode #214 "Bodyguard of Lies".
Bellamy works to sabotage the acid defense system used by Mount Weather in episode #214 "Bodyguard of Lies".
Jaha enters the strange mansion and finds himself talking to a hologram in episode #216 "Blood Must Have Blood, Part 2". Murphy finds his way to the mansion after being trapped in the bunker and talks to Jaha in episode #301 "Wanheda, Part 1".
Murphy enters a fancy bunker after landing on the beach and finds a video from someone before the bombs in episode #216 "Blood Must Have Blood, Part 2". He finds himself trapped in the bunker for several months in episode #301 "Wanheda, Part 1".
Echo leads the Sky People through the hidden tunnels underneath Polis in episode #303 "Ye Who Enter Here". Murphy and Pike saves Bellamy's group and they run the elevator up to the top of the tower in episode #315 "Perverse Instantiation, Part 1".
Marcus marvels at Polis when the crew arrives for the negotiations in episode #303 "Ye Who Enter Here". Lexa battles Roan in episode #304 "Watch the Thrones". Octavia talks Indra out of her funk in episode #307 "Thirteen". Roan escorts Clarke into town to draw Ontari out in episode #315 "Perverse Instantiation, Part 1".