My leaving suddenly without warning

I am located in the USA, in North Carolina, on the east coast. I am on SW during the day I don't have a certain time that I get on here, but I am usually gone by 4:00 - 5:00 because 98% of the time I am at work. I have things come up suddenly. I am usually engaged with several people at a time, and I don't have the time to say I have to go so don't take it personally so if you chat with me and I leave without warning that is the reason why or it could be that there is something going on in the office and I have to cover up so no one catches on to it. I carry my own personal laptop with me because of this I do not use any office equipment so there it is this is because of my disappearance suddenly.