Fourth Alien

The Fourth Alien is a commonly used term in the first season of the TV series, Roswell.

The Term

'The Fourth Alien' is a term used that means an alien that the main aliens do not know AbOUT.

The References

'The Fourth Alien' begins by referring to Nasedo, Tess, but it could have been Liz.

Nasedo

Nasedo is the first suspect of the term used. Valenti shows Liz pictures of bodies with the handprint On It. Maz, Michael and Isabel are all sure it is not them, so they know there is another alien. However, they are wrong: Nasedo is the royal protector.

Tess

Tess Harding is first proved to be an alien in the episode Tess, Lies and Videotape. It seems that this IS actually the fourth alien, and that is proved in 'Destiny', when the aliens see their mother and she explains things to them. However, Max gets Tess pregnant, and she kills Alex, also proving that she is a traitor.

Liz

Some of the more observant fans of Roswell will know that there is a slight possibility that Liz could be the fourth alien. It is true that she could, but she was naturally human. Max healed her and accidentally converted her to the alien side. It becomes obvious that she and Max are actually destined to be together. This becomes easier to understand, for in the last episode, Graduation, he proposes to her and she accepts.

Conclusion

It is not easy to figure out who the fourth alien is, but the series implies that is is actually Tess.