Missing characters

Rarely in games is seen that the characters simply disappear.I have an idea to discuss it,but perhaps the place to start is to list games that I'm going to touch:Modern Warfare 3,GTA 3,Half-Life 2 episode 2 & 3.

MW3:Derek frost Westbrooke was the protagonist in levels for Delta.13 Oct 2016 he saved from Berlin the daughter of the President of Russia Boris Varshavskogo,but failed.The day after the detachment is somewhere in Siberia again decided to save her,but frost was certain McCoy.I definitely saw a topic about him missing the game forum.

GTA 3:Donald Love was the employer of the protagonist.After a number of jobs the protagonist came to him and found just a deserted roof.I'm not sure,but his disappearance also seems to have a theme devoted.

HL:Barney Calhoun was a friend of the protagonist,for HL2:EP1 he evacuated the residents of the city.In the next part, he did not appear and was not even mentioned,which is quite strange.It is unlikely that he died from the explosion,was evacuated earlier because of Gordon.I searched the topic of his disappearance,did not find,but saw some comments that discuss that strangely he disappeared.I hope I am not repeating myself.Let the other characters remember,but first let's mention the name of the game.