There's nothing to tell, really.
I hadn't been on speaking terms with my dad for years. Then we bumped into him, and he invited us out to dinner, which I didn't like the sound of, but H wanted to be nice and smooth things over, so he encouraged me to go.
It was a Mason's Ladies Evening.
The Worshipful Master of each lodge changes every year - they rotate through the ranks. They hold the Ladies Eve annually, so that each year, the wife of the Master, and all the other wives are basically made a fuss of, by way of a thank you for letting their husbands go out to play.
It was good fun, and we met a lot of really nice people there, and enjoyed it.
My dad invited H & my brother-in-law to join, which they eventually did. Their outlook on it is that it's a place they can socialise, and know that, unlike going to a bar, they never have to share the company of drunken, brawling thugs. It's just civilised.
When I've asked him about the ritual side of things, he's said it's just a bit like religion, but without a 'God' as such being worshipped. The rituals are all basically lessons / reminders about treating everyone as your family (apart from drunken, brawling thugs I presume

), and is like the glue that binds them together - a thing they have in common - like maybe if it was another kind of club, it might be an appreciation of football or whatever.
There are social events fairly regularly, and money raised goes to charities, chosen by the Masons and wives.
The image that people have of them doing dodgy favours for each other (such as police members getting people's parking tickets waived) is entirely wrong. It would be considered bad form for one member to even ask another a favour of that nature.
Re the suspicions of occult goings-on, these people don't even have the first idea what you're talking about, and certainly H doesn't even believe such things really happen in the world, let alone show any interest in taking part in them. Now, whether there's any truth in it at a very much higher level, I've no idea.
It's actually a bit of a bore at their level. Sorry to disappoint.