(CNN) Michael Phelps opened up to CNN about his mental health struggles . It's one of several long reads you can settle in with this weekend. For now, here's what you need to know to Get Up to Speed and Out the Door . (You can also get "5 Things You Need to Know Today" delivered to your inbox daily. Sign up here .)

1. G20 summit

There are a ton of story lines coming out of the G20 summit in Germany, but none bigger than today's mano-a-mano showdown between President Trump and Russian President Vladimir Putin . How will Trump, a newcomer to politics and diplomacy, fare against the veteran Putin? Will Trump directly chastise him for Russia's interference in last year's elections? (Senate Democrats say he'd better .) Putin's been known to rattle world leaders in one-on-one settings (like the time he brought a dog to a meeting with Angela Merkel, who's scared of them), so it'll be interesting to see if he tries some kind of gambit with Trump.

Meanwhile, protesters and police have been mixing it up on the streets of Hamburg. Police this morning used water cannons to push out a group of protesters staging a sit-in on a city street. Protesters say they want to make it difficult for world leaders to move about the city.

2. Russian spying

JUST WATCHED Sources: Russia steps up spying efforts Replay More Videos ... MUST WATCH Sources: Russia steps up spying efforts 04:23

3. Ethics watchdog

JUST WATCHED Government ethics watchdog Walter Shaub quits Replay More Videos ... MUST WATCH Government ethics watchdog Walter Shaub quits 01:27

4. Georgia slayings

It's the kind of crime that's simply unthinkable -- four children, all younger than 10, stabbed to death in their own home . And the prime suspect is their own mother. Isabel Martinez, 33, was arrested and charged with murder in her children's slayings. Police say the suburban Atlanta mom also stabbed the kids' father to death. A fifth child, a girl, was injured, but her condition is unknown.

JUST WATCHED 4 children stabbed to death in Georgia Replay More Videos ... MUST WATCH 4 children stabbed to death in Georgia 01:24

5. Gonorrhea

Well, this is just downright scary. Gonorrhea is becoming harder -- and in some cases, impossible -- to treat with antibiotics. The World Health Organization says the bacteria that causes the sexually transmitted disease are becoming smarter and more resistant to antibiotics, so a new class of antibiotics will need to be developed to fight them. Gonorrhea is among the types of bacteria that health experts say pose the greatest threat to human health because of their antibiotic resistance.

JUST WATCHED How bugs become superbugs Replay More Videos ... MUST WATCH How bugs become superbugs 00:58

NUMBERS OF THE DAY

18

The number of states suing Education Secretary Betsy DeVos over her delay in implementing an Obama-era rule on student loans.

2040

That's the year France wants to end sales of gas and diesel-powered vehicles as it fights global warming.

BREAKFAST BROWSE

People are talking about these. Read up. Join in.

(Not) colorblind

Tupac broke up with Madonna partly because she's white , according to a newly discovered letter written by the late rapper.

Bros forever

Power trip

Elon Musk promises to end blackouts in south Australia by building the biggest lithium ion battery the world's ever seen.

Outrage with a purpose

A mom's Photoshopped picture of her baby's " diamond-pierced cheek " sparked exactly the conversation she wanted about piercing and circumcising kids.

Traffic jam

Jakarta dumped its HOV lanes , then watched as its rush-hour traffic went to hell.

QUOTE OF THE DAY

"We will put American boots on the face of Mars"

Vice President Mike Pence, channeling his best JFK, to NASA employees in Florida . Pence said we're going back to the moon, too.

JUST WATCHED Pence congratulates new NASA astronaut class Replay More Videos ... MUST WATCH Pence congratulates new NASA astronaut class 01:07

AND FINALLY ...

Rockin' out