Artefact Site

Alien Activity Site Mission

Alien Activity Site (Seabed)

This mission is a raid on a freshly activated Alien communications site. There are 2 levels to the site, the seabed with its Alien pyramids and a hidden Alien complex.

Source: X-COM Terror From The Deep Artefact Site Seabed assault mission briefing

Alien Acitivty Site (Alien Complex)

Having negotiated the Alien structures and entered the complex the mission goals are clear. Penetrate the heart of the Alien facility and destroy the Synomium Molecular Control Device to complete the mission.

Source: X-COM Terror From The Deep Artefact Site Alien Complex assault mission briefing

Artefact Sites are a 2-part mission. The seabed stage of the mission is fought in a series of underwater pyramids while the second level is fought in a mazy alien complex.

As with ship and port attacks, Artefact Sites are announced instantaneously the moment they are generated on the map. The alert message describes them as alien "activity", but thereafter they are referred to as "Artefact sites".

Artefact Sites start to appear some months into the game as an alternative to the various types of terror sites. After the 12th Artefact Site, they will revert to standard terror missions.

Artefact Sites are often treated with the same urgency as Terror sites. Though lacking a civilian component, they are longer and more dangerous and have greater repercussions. Failure to attend to an Artefact Site can result in a very large -2,000 points while failure to destroy the artefact site is worth an instant -750 points.

Though the penalties are great, so are the rewards. Destroying the Synonium Device alone is worth 750 victory points before adding in the mission score from equipment recovered and enemies defeated.

While costly to ignore, it is possible to complete all the research and submarine construction necessary to embark upon the T'Leth mission without having to fight any Artefact site missions.

Artefact sites are short-lived, typically lasting about 5 hours. Because of their their short durations and depths, you will not always have the luxury of arriving in ideal lighting conditions. As with other short-duration sites, Artefact Sites will remain on the map if targeted by at least one X-COM submarine after their operational duration has expired.

Synonium Device

The "Synomium Device" is the so called "Artefact". As explained in the mission text the Artefact Site is a revived communications site where the artefact acts as hub for the aliens' standard means communication: Molecular Control. Similar devices are present in alien colonies, presumably excavated from Artefact Sites and installed in the colonies to coordinate their operations via the MC network.

The device can be destroyed by all weapons other than melee weapons.

An Artefact Site and Alien Colony is officially declared as destroyed on the destruction of the Synonium Device, no matter what fate befalls the X-COM aquanauts after that.

Finding the Device

• 

  The path to the device

• 

  The Synomium Device (silvery object, top left)

The Synonium Device is housed in a very distinct matte black hall with a central elevator shaft as depicted in the first image above. The second picture shows the chamber where the Synonium Device is stored on the upper-most level. The device itself is a pedestal with two rotating rings.

Be warned that the black chamber is fiercely guarded by many Tentaculats and armed Aquatoids hiding in upper level cubbyholes.

A very quick, dirty but otherwise safe way of destroying the device without facing most of the opposition is to fire a ranged explosive projectile immediately up at the ceiling under the device.

Mission structure

The mission itself is a 2-part assignment. The first part is on the seafloor with green pyramid buildings. The objective here is to get to the site entrance (or kill all the aliens). The site entrance is in a long, thin pyramid with only 1 floor. The pyramids are quite large, spanning 3 floors and with many "windows" cut into the walls. Be watchful of snipers from many elevated angles.

The second part is inside a 4-floor structure. There will be two randomly placed XCOM spawn points on the top floor (L3). However, some team members may be placed at any level including L0. L0 is the main floor and connects to the shaft leading to the Synomium Device. The Synomium Device is located on L3, and you must go up the shaft to get to it. Destruction of the device will complete the mission. Your team can then leave, clear the site. If your team is defeated after destroying the device, the site will still be treated as having been cleared.

The room surrounding the shaft leading to the Synomium Device is heavily guarded with Tasoths, Aquatoids, Tentaculats, and a Hallucinoid. There are coves containing aliens at each of the 4 corners on L1 (typically Tentaculats), as well as 2 larger balconies on L2 (typically Tasoths or Aquatoids). Given there higher elevation, these aliens can be quite hard to see. A Hallucinoid may be at the bottom of the shaft on L0. Several Tentaculats are usually found on L2 in a side room off the shaft, or in the shaft itself. The room actually containing the Synomium Device is usually unguarded.

Points

750	Successful destruction of the Synomium Device
-750	Landing at the mission, but failing to destroy the Synomium Device
-2000	Ignoring the mission site

Enemies encountered

(Note, factual data of crew formation and weapon setups needed from the executable needed to complete this section)

Typical aliens defending Artefact sites include Tasoths, Tentaculats, Aquatoids, and Hallucinoids.

In particular, there may be a large number of Tentaculats on the lower level (as many as 10 have been reported). A recent mission on Superhuman had 44 aliens present, though some were XCom agents turned to zombies. Up to 20 aliens can be expected per mission part.

Equipment Recovery

Being a 2-parter mission, what equipment is recovered will differ depending on what patch has been applied to your game.

TFTD v1.0

Only equipment carried on aquanauts will carried to the next map. Equipment left in the transport will be lost.

TFTD v2.0 or CE

If the first map is cleared, all equipment is returned to base if the second part is aborted or cleared.

In all versions, if you attempt to leave the map from the transport (level 1) or the exits (level 2), equipment in the exit area as well as what's being carried by aquanauts in the exit area will be recovered.

Recoverable Alien Sub Artefacts

If all aliens are defeated, you will be able to recover the various collectible base elements on the second map. For example:

Ion-Beam Accelerators	10
Alien Sub Construction	1
Alien Cryogenics	12
Alien Learning Array	1
Alien Implanter	2
Aqua Plastics	484
Alien Re-Animation Zone	3

Remember that these values are an example only. Actual values will differ depending on the types of artefact site map modules that are generated in the second part and what sort of damage, if any, was dealt to them during the battle.