PHP magic methods and Security

I'm in the middle of a programming challenge and just needed a way to follow the code I have to review :

<?php
  require_once( "settings.php" );
  class Database{
    function __construct(){
      $this->setDefaults();
    }
    function setDefaults(){
      if( !isset($this->host) ) $this->host = DB_HOST;
      if( !isset($this->user) ) $this->user = DB_USER;
      if( !isset($this->pass) ) $this->pass = DB_PASS;
      if( !isset($this->name) ) $this->name = DB_NAME;
      $this->description = $this->user."@".$this->host."/".$this->name;
    }
    function connect(){
      $this->connection =  new mysqli( $this->host, $this->user, $this->pass, $this->name );
      if( !$this->connection ) die( "Connection to ".$this->host." failed!" );
    }
    function query( $sql ){
      if( !isset( $this->connection ) ) $this->connect();
      $this->result = $this->connection->query( $sql );
      return $this->result;
    }
    function fetchRow(){
      return $this->result->fetch_assoc();
    }
  }

  class Flag{
    function getFlag(){
      return file_get_contents( FLAG_PATH );
    }
  }

  class Page{
    function __construct(){
      $this->elements = array();
      $this->html = "";
    }
    function __wakeup(){
      $this->compile();
    }
    function addElement($el){
      return $this->elements[] = $el;
    }
    function render(){
      if( empty( $this->html ) ) $this->compile();
      return $this->html;
    }
    function compile(){
      foreach( $this->elements as $el ){
        $this->html .= $el->render();
      }
    }
  }

  Interface Element{
    function render();
  }

  class SelectElement implements Element{
    function render(){
      if( empty( $this->aItems ) ) return "";
      $html = "<select>\n";
      foreach( $this->aItems as $k => $item ){
        $html .= "<option>".$item."</option>\n";
      }
      $html .= "</select>\n";
      return $html;
    }
  }

  class ObjectDescriber{
    function __construct( $obj, $prop, $type ){
      $this->obj = $obj;
      $this->prop = $prop;
      $this->t = $type;
    }
    function __toString(){
      if( $this->t == "m" ){
        return $this->obj->{$this->prop}();
      }else{
        return $this->obj->{$this->prop};
      }
    }
  }

  class DatabaseDescriber extends ObjectDescriber{
    function __construct( $db ){
      $this->obj = $db;
      $this->prop = "description";
      $this->t = "p";
    }
  }


?>

Challenge:

Get the value of Flag-> getFlag ()