Gangplank is a Council mission. This mission will be available sometime after the player completes the mission Confounding Light. Like all Council Missions, the mission is initiated by the player being contacted by The Council.
- Destroy or disable all the ship's power conduits (6 total).
- Eliminate all alien defenders.
This mission takes place inside an airborne Alien Battleship which means the map layout is nearly identical to that of Battleships that can be encountered on UFO Crash Site or UFO Landing Site missions but with the unique exceptions of the six power conduits placed inside and the Chinese cityscape that can be seen passing below this Battleship. Additionally, the map "ends" shortly before the door to the bridge, so the large room before it is actually the final room of the level, as well as there being a few more of those "elevator beams" around the ship.
The alien forces encountered in this mission consist primarily of Thin Men who are present on the map at the start of the mission, and who will drop into the map as the squad advances. Additionally Sectoids and Chryssalids are encountered as the mission progresses; near the end of battleship you will meet a Cyberdisc and a Muton.
The power conduits can be deactivated, similar to the Power Nodes in bomb disposal missions (there is no time limit, so feel free to take your time), or can simply be blown up (no penalty of lost Elerium or damaged Generators if you do so, but an insignifcant notch less of Alloys for each destroyed conduit). Plus the Cyberdisc; grenades (particulary Alien Grenades from any captured Mutons in the previous Slingshot mission), and a Heavy, especially with HEAT, are recommended. As this mission can appear as early as the second month, Zhang himself would be suitable.
- Low Profile is disproportionately useful on this mission, due to the extent of low cover available in high places. Same with Damn Good Ground and associated elevation-bonus abilities/medals.
- You will face a Cyberdisc that doesn't mind patrolling through a door. It will not have any Drones with it.
- If you do not have Laser weapons yet, it may be worth your while to bring Reaper rounds and/or SCOPEs, or Squadsight sniper(s) or very accurate Heavy soldiers.
- Due to the lack of a time limit, you should start each movement up with full magazines and in good supporting positions.
- If you don't wish to save after each successful engagement on Classic/Impossible, you need to have a very high understanding of how line of sight and cover rules work. This is due to the large amount of elevated terrain in the form of small platforms etc.
Additionally, completing the mission awards the player with the "The Bigger They Are" Achievement.
- This mission will happen not too long after the Confounding Light mission (in vanilla EU: if both of the earlier Slingshot missions were completed the first time around, this will be in April. In Enemy Within: late May). The biggest danger will be how under-equipped your soldiers will be, particular against that Cyberdisc, however you can put this mission off for as long as you deem necessary as the council will offer it to you every few days, this can allow for wounded soldiers to be returned to active duty, or allow you to collect money to pay for your more powerful weapons.
- You can no longer put this mission off as of the Enemy Within Expansion. But at least the later placement will make your tech and soldiers better suited to take the ship.
- You will receive two Fusion Cores from the battleship: while you could research the Blaster Launcher and Fusion Lance weapons this early, the Research Time and Weapon Fragment requirements for them make it unfeasible. Considering that the Lance can only be installed on the Firestorm, and high HP enemies that would call for a Heavy with the Launcher won't appear for a few months, and that so much else should have priority for research, it's better to sell one Core, and save the other for when you've got the time for it. If you're playing with Marathon enabled, don't sell any of the Fusion Cores because you'll need two to build each Blaster Launcher.
- Additional spoils include a massive supply of Elerium, Alloys, Computers, and Power Sources. As you will probably have much more than you can actually use at this point, you can sell some portion of these, keeping XCOM funded for quite some time (base excavation and facilities, for example, would be a good expenditure this early in the game, as most facilities have a constant price throughout the game). Anything you do sell you will probably make up from regular UFO Assaults by the time you have anything to use them for.
- If you destroy the power conduits instead of turning them off, you'll only lose a few units of alien alloy.