Cat vs Dog.....................

Thomas heathcliffe is fine, he is still residing at our old building and being taken care of by my old neighbour. but she wants to move and so now he HAS to stay at home and he and Brutus have to get along. Easy? I don't think so, I am going to fetch him AGAIN today and take him home for the hundredth time and I don't actually know WTF to do. The dog and the cat do not like each other and even though this is not the reason Thomas roams (he did it long before the dog came) I have to make it work somehow. I have tried introducing them through a cage, I have had to lock one up and let one out at a time I feel guilty about the one that is locked away. I want my cat & my dog both to be able to lie in the lounge at night with us and though that might be a pipe dream that is what I want. I couldn't get a big dog puppy and wait for it to grow up because we needed the security straight away. I sometimes think I shouldn't have got Brutus because of the cat, but if we didn't we would have still been scared and uncomfortable in our own home. Thomas is hardly at home so in a way it is his own fault if he is the one locked up. He is a maniac at night and keeps us all awake wanting to escape etc. I can't make a seven year old cat stay indoors after all these years, he is used to roaming. I wish T was here to help me when I get home today I wish the animals would get along, I wish I could "fix" this....................any suggestions?