LONDON — David Cameron would complain that Theresa May was like a submarine, disappearing for months only to emerge at the time of her choosing. As prime minister, she is behaving no differently.

Having spent months preparing for her big Brexit reveal, she resurfaced with intent Tuesday, taking control of Britain’s exit from the European Union just as it threatened to run away from her.

Reporters, starved of phone signal and breakfast, had trudged up the stairs from their dingy holding pen in the bowels of Lancaster House in central London dreading more platitudes and soundbites.

They needn’t have worried.

Flanked by giant watercolors of old England and portraits of royals and statesman, May set out her stall with a clarity that left few in Westminster — or in Europe — complaining. Not everyone will like what she is saying, but May can no longer be accused of not knowing what she wants.

From the single market (No) to EU citizens’ right to stay in Britain (Yes), via 10 other points in between, May laid out what she was aiming for and what she has given up on.

The skill in the speech was the powder she kept dry beneath the sound of the gunshots fired at Brussels overhead.

Here are six takeaways from a day of drama — and clarity.

May takes control

This U.K. prime minister was made in the Home Office. She likes control, order, competence. In today’s speech, she took charge of the upcoming Brexit talks by deciding what they will be about.

She will not even try to squeeze new concessions on free movement out of Brussels while staying in the single market. Instead, Britain will leave the free-trade bloc of its own accord.

Britain wants a trade deal so that it can wriggle free of almost all of Europe’s legal and economic tentacles. In setting out her stall this way, May lowered Britain’s demands but took control over what's on the table.

UK hardball

“No deal for Britain is better than a bad deal for Britain,” warned May, upping the stakes considerably. Herein lies the crux for Brussels: Is she bluffing?

May knows that she will not get a good deal if, in the end, she has to accept what she is given. In warning that she is prepared to quit without a deal, the U.K. prime minister is adopting a classic negotiating tactic. Cameron tried it by threatening to campaign for Brexit if he didn't get the renegotiation of U.K.'s relationship with the EU that he had promised British voters but no-one ever believed him.

In May there is something of the zeal of the convert. She didn't back Brexit during the referendum campaign but today she warned that punishing Britain would be “an act of calamitous self-harm” for Europe, insisting Britain “could not accept such an approach.”

Hard Brexit, but soft around the edges

Britain will leave the single market, the jurisdiction of the European Court of Justice, much of the customs union and dramatically cut is financial contributions to the EU budget. That sounded like a hard Brexit to most people in Westminster. Brexiteers in Parliament were certainly cock-a-hoop.

But look more closely and May’s hard lines begin to blur.

On financial contributions, the PM ruled out “constantly paying very large sums.” However, there might be elements of cooperation that the U.K. will remain a member of and would be prepared to “make contributions to.” Opacity defined.

On immigration control, May also seemed strident: total U.K. control. Again, though, there was no detail. “We will get control of the number of people coming to Britain from the EU,” she said. An emergency break on migration numbers that was floated by Cameron but rejected by EU leaders would pass this test.

On the customs union, she even spelled out her flexibility. Anything that stopped Britain conducting its own free trade deals outside the EU was a no-no. This leaves plenty of room for deals that don’t.

Even on the single market, May hedged ever so slightly. The new agreement “may take in elements of current single market arrangements in certain areas,” she said. May listed some examples: the export of cars and lorries or the freedom to provide financial services across national borders. May is looking for special carve-outs. The question is, what price will she pay?

It’s all about the transition

The prime minister might have seized control of the agenda but she has sacrificed time. In calling for everything, including a new trade deal between Britain and the EU, to be wrapped up in two years she has bound herself in a schedule most people in Brussels think is impossible.

A successful deal will rest on the length and scope of “the transition,” which May admitted was crucial to avoiding a cliff edge for the economy.

The PM attempted to dress up the plea for time in strident terms. Britain would not accept an “unlimited transition,” she said as if anyone from any European capital would tolerate Britain hanging around but refusing to leave forever.

“For each issue, the time we need to phase-in the new arrangements may differ” — Theresa May

She called for a “phased process of implementation.” Again, this was open-ended and potentially wide-ranging.

A transition might be about immigration controls, she said, or the new customs agreement, or criminal justice matters. Or even how to regulate the City of London. “For each issue, the time we need to phase-in the new arrangements may differ,” she said.

The problem for May is that the EU is fine with a transition, so long as Britain sticks to the rules of the club. May admitted the “arrangements” would be a matter of negotiation, but she will be hard pressed to enter the 2020 general election without full control of many of the Brexit promises, particularly immigration.

MPs get a vote – but no power

“The Government will put the final deal that is agreed between the U.K. and the EU to a vote in both Houses of Parliament, before it comes into force,” May announced, sending the pound surging.

But what happens if MPs reject the deal? When asked to clarify whether a No vote would simply mean the U.K. exits the European Union on World Trade Organization terms, the prime minister's official spokeswoman said: “Whatever happens we will be leaving the EU.”

So, MPs will get a choice between the PM’s deal and a disorderly exit. A year before a general election, that doesn’t look like a good choice for anyone.

Scotland ignored

Few lines rang more hollow than May’s promise to “put the preservation of our precious Union at the heart of everything we do.”

Scottish First Minister Nicola Sturgeon warned that leaving the single market was a red line. May ignored her. Sturgeon was quick to respond that exiting the single market was not in Scotland's interest and would provoke a reaction north of the border.

Vague promises to repatriate powers from Brussels to Edinburgh do not disguise that fact that May’s speech makes an independence referendum in Scotland more likely.