How do I accept side quests?

[Larre]

Got through the first night mission and in the tower there was a quest to activate a trap or something to kill many of them night creepers or what ever they are called in one blow.
The reward was a powerful weapon and some xp. A red thing came up on my screen and the reward was shown underneath it. The only thing on my creen was a button to equip an UV light, nothing happened when I hit that button. And then there was a countdown from 3 to zero and the quest was gone.

I have googled, and asked friends and still I have no idea how to accept these kids of side missions what ever they are.

Help anyone?

[Maudy]

did this pop up when you were playing alone or with someone else? because if it popped up when you were with friends it might of been one of those competetive challenges

[Larre]

I was alone

[Larre]

I'm afraid to play anymore, dont want to miss out on any more quests before I know how to accept them lol

[dr.doom]

Don't worry, every sidequest can be done at any point in the game. Even when you finish the main story you can free roam and pick them up. When you open your map, quests are marked with "!".

[Larre]

Okey.. So this quest I'm taking about had a ! in the tower, talked to this npc and got that thing I described on my screen, the countdown from 3-0 and now the ! is gone?
I dont understand what you mean, because now this npc wont talk to me. What do you mean?
Please explain how I can pick up the sidequest now when the ! is gone?

[dr.doom]

I think I know what you are talking about. There is a guy in the tower, that gives you quests about killing zombies. You need to kill let's say 40 zomibes in 2 min using baseball bat. It might be what you are talking about. This quest(it is more like a challange) needs to be completed for it to vanish. It is however not a storyline quest just mindless killing.