Prologue - the aliens make surreptitious contact

The car screeched to a halt.  Freeman was still recovering when
he found the door being opened for him.  As he stepped out of the
sedan, he glanced up to see the sunglasses and uniform of a
Marine lieutenant.  Once out of the car he became aware of
other, similar Marines.  They were all armed, even if only with a
holstered sidearm.  Why the sudden security? he wondered.

He was hustled up the stairs and through the front doors.  The
lieutenant buzzed him through the security checkpoint inside, then
abandoned him to leave the building the way they'd come.  Freeman,
alone in the hallway, stood looking backward at the imposing security
door.  He felt a brief bout of uncertainty.  It tinged on
fear, and he fought for a moment to quell it.  Wheeling, he
distracted himself by hurrying through the familiar maze.

.......

Freeman had only just entered the conference room when
he heard his name.

"You must be Dr. Haight!  It's a pleasure to meet
you."  The speaker rose from his plush seat at the conference
table and strode to intercept him.  The two shook hands, and
Freeman noted his greeter's smile.  It was calm, professional,
detached.  Surely things weren't as bad as he had feared earlier.

Freeman evaluated the other man.  No uniform, no
other signs of rank.  He was a stranger, and although he was
carrying a badge, it didn't identify him by name.  An academic?

"Yes.. yes, likewise," Freeman managed, smiling.  "I'm
afraid you have me at a disadvantage, though."

"Ah, yes.  Fritz Hume, at your service, sir."

Freeman felt presences behind him and stepped out of
the doorway; Hume followed suit.  Several of the Joint Chiefs were
arriving, along with their aides, and a few other men or women Freeman
couldn't identify.

Everyone found a seat, somehow; the meeting was called
to order.  Freeman found himself sitting beside Hume, who sat
reclined and steepled his fingers, like a chess master waiting for his
opponent.

.......

"This communication was intercepted on one of our most
securely-encrypted radio channels.  This should not have
happened.  It could not have happened.  But all our analysts,
and all our data, say it is.  It repeated itself three times, with
an hour between each occurrence, then shut off.  Dr. Hume, would
you give us the NSA's latest findings on this intrusion?"

Freeman glanced to his left at Hume, who nodded and
rose lithely from his seat.  "With our current computing capacity,
and with the cipher algorithm, breaking the key via a semi-optimal
attack would require three thousand seven hundred and five
years."  Emotional murmurs erupted from those seated at
the conference table; the chair coughed loudly and spoke loudly enough
to regain control.

"The NSA's staff has informed me that they are working
in full cooperation with the Unified Intelligence task force to
determine if this represents a compromise.  Other.. other groups
have suggested an alternate explanation, and we are here to give it the
most serious consideration possible.  You will understand when you
read the communication itself."  An aide began to pass around
stapled sheafs of paper.

Freeman received his and passed the rest along. 
He glanced over at Hume, and found the man was actually smiling as he
read over his copy.  Freeman returned his attention to his own.

Underneath the document-classification headers was the
message itself: a simple, plain-spoken piece of text.  But as he
read it, Freeman felt the world fall out from below him.

FOR UNITED STATES GOVERNMENT ADMINISTRATION

WE ARE EXTRA-TERRESTRIAL INTELLIGENCE WISHING TO MAKE
CONTACT

PREVIOUS OBSERVATION SUGGESTS SOCIAL PANIC UPON OPEN
REVELATION

WE ARE INTERESTED IN ESTABLISHING RELATIONS

THIS COMMUNICATION CHANNEL TO BE MONITORED FOR REPLY IN
ENGLISH

VERIFICATION CODE 11011101010101110110 WILL BE
TRANSMITTED VISUALLY

VERIFY JUNE 10, 2015, 12AM EASTERN STANDARD TIME

RIGHT ASCENSION 4 HOURS 30 MINUTES DECLINATION 14
DEGREES

Freeman glanced around, looking from face to
face.  Some of the Joint Chiefs looked shocked.  Others
looked frankly disgusted.  A few hostile whispers began to break
out before the chairman brought his gavel down hard.  The room
fell silent.

"We are not in the habit of playing pranks of
this magnitude on one another, gentlemen.  This message is either
false, or it is true.  If false, it represents a critical failure
in our security apparatus.  If true, it means unforeseeable
difficulties for our society.  Either way, John Q. Taxpayer is
relying on us to keep our heads clear."

"The National Security Council is meeting
later today.  By tomorrow, we need to have something - anything -
substantial to go on.  The President will be in the meeting, and
she will want answers."

Freeman nodded slowly.  He began to understand
his role in this.

"Doctors Hume, Haight, Cutler," an aide
called.  "You are requested to join a task force investigating the
'verification' signal."  In a daze, he only half-heard the other
assignments being handed out: a directive to Unified Intelligence to
investigate a possible leak, requests for information from the Air
Force about its space activities, an order to gear up for a heavy-duty
counter-espionage campaign, and more.  He ignored them.  He
had his own part to play now.