[Mr. Robert] released me with a shove and pointed to the cemetery where they buried white people. "Go pray for her that owned you, girl." (1.34)
Whoa—that was cold. The least he could have done was let Isabel finish paying her respects to her mother before she visited her mistress's grave. Nonetheless, the rules of slavery are so strict that they don't even allow her the dignity of saying goodbye to her mother. According to her master, her loyalties lie with Miss Mary, not Momma.
"Wait," Jenny announced loudly. "I'll… I'll take them."
The table froze. A person like Jenny did not speak to folks like the Locktons or Mr. Robert, not in that manner. Lockton stared at her as if she had grown a second head. (3.92-93)
Social class distinctions are pretty huge in the lives of people like the Locktons. That's what makes Jenny's statement that she'll take the girls so shocking—according to social rules, she shouldn't even be talking to these people at all. Since Madam takes precautions to increase her offer for the girls so Jenny can't counter it, this social code also gets Isabel and Ruth sold to the Locktons rather than being allowed to stay with a woman who's the closest thing to family they've got.
If I opened the gate, I would be a criminal. Slaves were not allowed after the sunset without a pass from the master. Anyone who caught me could take me to the jail. (10.22)
When you think about the massive amount of regulations Isabel practically collapses under as the Locktons' slave, the risks she attempts to take to secure freedom for her and Ruth become pretty astonishing. She recognizes here that the most overwhelming task ahead of her isn't going to Bellingham's and ratting on Lockton—it's being brave enough to take the first step out of the gate and violate the rules.
[Madam] flew into the bookcase, causing several books to tumble to the ground. I almost reached for her but was afraid to anger Lockton any further.
"I command you to stay here, Anne. This is your duty and you will obey me." (7.32-33)
As if he doesn't have enough people to order around already, Lockton seems to consider his wife little more than one of the house servants. It's true that she's pretty disrespectful to him—what husband or wife would put up with the kind of stuff she says? Still, telling your wife that it's her duty to obey you is laying on the rules a little thick.
Colonel Regan fastened his collar without looking at me. "The law binds my hands and my actions. You must return with your mistress," he said, concentrating on his task. "Even during times of war, we must follow the rules of propriety and order." (21.112)
Wait a minute… It's considered proper and orderly for humans to own other humans and be physically abusive? Not in our book. Colonel Regan's statement is yet another example of the strict observance of slavery in colonial society—even if it means Isabel's life.
"We are now led by men from Virginia, I am told," [Madam] said, "land of my birth. I assure Your Honor that in Virginia, we do not tolerate the rebellion of slaves."
The judge nodded. "Once kindled, rebellion can spread like wildfire." (22.34-35)
The judge's statement here raises some questions about why the rules of this society are in place to begin with. Obviously, they're placed on slaves to keep them from rebelling and make them subordinate to their masters. But could he also be talking about the spread of the rebellion against the British? Don't forget—King George placed a ton of regulations on the colonists, too, and we all know how that turned out.
I thought of what she said and found a slim thread of hope to grasp hold of. "Begging pardon again, ma'am, but do I work for you now?"
[Lady Seymour] let the curtain fall. "I am afraid not. Anne insists that you be returned to her household as soon as you are able. The law supports her position, I fear, and in these unsettled times, there is little remedy." (24.31-32)
Once again, the law, in all its infinite wisdom, condemns Isabel to be sent back to work for a woman who broke a painting over her head, had her branded, and sold her sister out from under her. Isabel literally has no one on her side in this matter, not even the rules of a society that's allegedly seeking freedom.
[The pass] was signed with lots of fancy titles that belonged to the colonel and the commandant, and the King Himself. I wished that there would have been a space for Her Majesty, Queen Charlotte of Great Britain to sign it, too. She and me shared a birthday now, for I was reborn as Isabel Gardener and that paper proved it. (44.101)
In the end, Isabel chooses to use the law to her advantage. Because she has the rare skill of being able to read, she's able to fill out the pass required in order to be a free slave, taking the lead to free herself rather than wait for someone else to do it for her.